Add IDE configuration and checkstyle

Fixes #89

ide-configs/README.MD

@@ -0,0 +1,10 @@
+# jDiameter IDE Configurations
+
+In this folder you will find configurations for IDEs to proper format and style check the source files for jDiameter project.
+
+The `checkstyle.xml` file is used by maven configuration and can be imported to most IDEs for  checking code style. It requires a plugin to properly function, which can be obtained at:
+  - [Eclipse Checkstyle Plugin](http://eclipse-cs.sourceforge.net/#!/)
+  - [CheckStyle-IDEA](https://plugins.jetbrains.com/plugin/1065-checkstyle-idea)
+  - [Checkstyle Beans](http://plugins.netbeans.org/plugin/3413/checkstyle-beans)
+
+Additionaly configuration files for proper code formatting are provided in the respective directories.

ide-configs/checkstyle.xml

@@ -0,0 +1,107 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE module PUBLIC
+          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
+          "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+<!--
+
+    TeleStax, Open Source Cloud Communications
+    Copyright 2011-2017, TeleStax Inc. and individual contributors
+    by the @authors tag.
+
+    This program is free software: you can redistribute it and/or modify
+    under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation; either version 3 of
+    the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>
+
+-->
+
+<module name="Checker">
+
+  <!-- Checks for whitespace                                                 -->
+  <!-- See http://checkstyle.sf.net/config_whitespace.html                   -->
+  <module name="FileTabCharacter">
+    <property name="eachLine" value="true"/>
+  </module>
+
+  <!-- Trailing spaces regex.                                                -->
+  <!-- See http://checkstyle.sf.net/config_misc.html                         -->
+  <module name="RegexpSingleline">
+    <!-- \s matches whitespace character, $ matches end of line. -->
+    <property name="format" value="\s+$"/>
+    <property name="message" value="Line has trailing spaces."/>
+  </module>
+
+  <module name="TreeWalker">
+
+    <!-- Checks for Size Violations.                                         -->
+    <!-- See http://checkstyle.sf.net/config_sizes.html                      -->
+    <module name="LineLength">
+      <property name="max" value="160"/>
+      <property name="ignorePattern" value="^\s*//.*|^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+    </module>
+
+    <!-- Indentation checks.                                                 -->
+    <!-- See http://checkstyle.sf.net/config_misc.html                       -->
+    <module name="Indentation">
+      <property name="basicOffset" value="2"/>
+      <property name="braceAdjustment" value="0"/>
+      <property name="caseIndent" value="2"/>
+      <property name="throwsIndent" value="4"/>
+      <property name="lineWrappingIndentation" value="4"/>
+      <property name="arrayInitIndent" value="2"/>
+    </module>
+
+
+    <module name="OneStatementPerLine"/>
+
+    <!-- Checks for imports                                                  -->
+    <!-- See http://checkstyle.sf.net/config_import.html                     -->
+    <module name="AvoidStarImport">
+      <property name="allowStaticMemberImports" value="true"/>
+    </module>
+    <module name="RedundantImport"/>
+    <module name="UnusedImports" />
+    <module name="IllegalImport">
+      <property name="illegalPkgs" value="junit.framework"/>
+    </module>
+
+    <!-- Modifier Checks                                                     -->
+    <!-- See http://checkstyle.sf.net/config_modifiers.html                  -->
+    <module name="ModifierOrder"/>
+    <module name="RedundantModifier"/>
+
+    <!-- Checks for blocks. You know, those {}'s                             -->
+    <!-- See http://checkstyle.sf.net/config_blocks.html                     -->
+    <module name="LeftCurly"/>
+    <module name="NeedBraces"/>
+
+    <!-- Checks for common coding problems                                   -->
+    <!-- See http://checkstyle.sf.net/config_coding.html                     -->
+    <!-- Disabled until http://sourceforge.net/tracker/?func=detail&aid=2843447&group_id=29721&atid=397078 is fixed-->
+    <!--<module name="DoubleCheckedLocking"/>-->
+    <module name="EmptyStatement"/>
+    <module name="EmptyBlock">
+      <property name="option" value="TEXT"/>
+      <property name="tokens" value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+    </module>
+    <module name="EqualsHashCode"/>
+    <module name="IllegalInstantiation"/>
+
+    <!-- Miscellaneous other checks.                                         -->
+    <!-- See http://checkstyle.sf.net/config_misc.html                       -->
+    <module name="UpperEll"/>
+    <module name="PackageAnnotation"/>
+    <module name="CovariantEquals"/>
+    <module name="ArrayTypeStyle"/>
+
+  </module>
+
+</module>