reorganized repository based on comments from @fgeorges about EXPath Package format:

1. renamed repository and package id to xqjson
2. moved expath package files into src directory to prevent non-package files from slipping into the .xar (e.g., readme, license, etc.)
3. renamed module namespace to be more specific (xqilla/functions > xqilla/lib/xqjson)
4. added a home element to cxan.xml
5. incremented version number to 0.1.4

Florent also suggested moving the eXist-db-specific files (repo.xml and icon.png) into an "exist" folder inside the package, but since eXist-db does not yet look for these resources there, I'm holding off on that suggestion for now.