Initial commit of astxml2wiki scripts

The astxml2wiki scripts parse Asterisk XML documentation and convert it
into wiki markup suitable for consumption by Atlassian Confluence. This
includes the following:

* astxml2wiki.py - Python script that pre-processes the XML, post-processes
  the generated Confluence wiki documentation, and pushes changes to a
  Confluence server
* astxml2wiki.xslt - Stylesheet that formats the XML into wiki text
* version.py - Basic Asterisk version checking gleefully stolen from the
  Asterisk Test Suite