Add script to build custom Solr release

This script is used to build custom Solr releases for use with
Yokozuna.  Currently Yokozuna relies on a custom patch to distributed
search.  Rather than require people to build this release during the
Yokozuna build this script will be used to create a custom release
which will be uploaded to Basho S3 and downloaded by the Yokozuna
build script.  This will simplify and shoten the time it takes to
build Yokozuna.
Update the no-stale-check patch for Solr 4.2.0

Solr 4.2.0 was updated to the latest HTTP Component library version
and broke this patch.  The new patch was made against the
`lucene_solr_4_2_0` tag from the github clone.

https://github.com/rzezeski/lucene-solr/commits/rz-no-stale-check-4.2
Make archive of custom build
Use solr-4.2.0-yz1 release
Update README with latest build process
Merge branch 'solr-build'