More complete clean target

Make sure to delete the solr dir and build dir generated at compile
time.
Upgrade to Solr 4.4.0

Upgrade to the custom Yokozuna build of Solr 4.4.0.

* Modify the `solr.xml` file to use the new format.  See http://wiki.apache.org/solr/Solr.xml%204.4%20and%20beyond

* Fix `grab-solr.sh` to not fail on mkdir.
Tweaks to build-solr script

* Use set -e so that script fails if patches fail to apply

* Add some additional checks for robustness
Update solr dist search patch to apply to 4.4.0
Update solrconfig.xml for Solr 4.4.0
Update default_schema.xml for Solr 4.4.0

See https://issues.apache.org/jira/browse/LUCENE-4963
Merge pull request #197 from basho/feature/rz/solr-4.4

Upgrade to Solr 4.4.0