Added configuration option to define the max number of results that can be returned by an ElasticSearch query
Make mappings explicit in ElasticSearch Adapter. Closes #359.
Merge branch 'master' of https://github.com/akeffalas/titan into indexing4PR

Conflicts:
	titan-es/src/main/java/com/thinkaurelius/titan/diskstorage/es/ElasticSearchIndex.java
Support for prefix queries and regular expressions in full text search.