simplified configuration for jGrouseDoc

[denis.r...@gmail.com]

I have performed the first cut for simplifying of jGrouseDoc
configuration.
All the configurable options are moved out into separate
jgrousedoc.properties file.
Certain options from the properties file could be also overridden from
the command line or via environment variables.

For example, by default the tool would process all *.js files.
If there is a need to process one file only (say, for troubleshooting
purposes) then it is possible to run the following command:
ant -DfileMask=foo/bar/MyFile.js

Check the latest version and let me know if the change is making your
life easier and what else should be added.

On a related note, for those who prefer to build jGrouseDoc from
source - the build script for jGrouseDoc itself had been modified to
create a jGrouseDoc distribution bundled with ANT (in case when path
to ANT installation was specified)

Regards,
Denis