Allow the regular expression-based Block and Permit lists to be edited from the web UI

[galacticstudios]

I propose making BLOCK_NAME_PATTERNS, BLOCK_NUMBER_PATTERNS, PERMIT_NAME_PATTERNS, and PERMIT_NUMBER_PATTERNS editable from the web UI.

I propose changing config.py so that those properties contain file names instead of dictionaries. The files would then have each line be a regular expression, optionally followed by a colon and a human-readable description.

A new web page would present the files' contents to the user and let him edit and save them, which would modify the files.

When screening an incoming call, instead of the CallScreener object holding an in-memory copy of the regular expressions, it would read them from the files.

[galacticstudios]

Forgive me for not doing this right, but I'm unfamiliar with git and github.

You can find an implementation of my proposed enhancement at my fork, https://github.com/galacticstudios/callattendant

[galacticstudios]

I've added another feature: the option to send an e-mail when a caller leaves a recorded message.