handling IGES data

[cbernardo]

The handling of IGES data at the moment is very limited; perhaps this can be improved by using my IGES library which is under development (https://github.com/cbernardo/libIGES). My IGES preprocessor currently handles the features (entities) which are most commonly used by MCADs although it does not currently handle some entities which the IGESconverter.C is interested in such as Ruled Surface.

At the moment when I test 'goview' I cannot visualize a basic cube or rod in IGES format. I am interested in the GoTools though since it may provide the basic functions which I need to render IGES solid model data which may include complex assemblies consisting of parts and subassemblies.