Merge pull request #3 from tikitu/master

Added a "test-jar" goal to the pom
renamed field sizes to field entries
Extended AbstractNodesTests with more handy basic functionality.
Switch to using ESLoggerFactory
upgraded to 0.20.X
upgraded travis.yml to 0.20.X
fixed a typo in a debug logging command
Update README.rst
Removed image from travis-ci due to repeated failures on travis' side.
Add an installation method via dropbox.
Removed a listnerThreaded command that is apparently no longer supported by ES.
Merge remote-tracking branch 'origin/master'
changed testing scheme for the latets releases
introduced MultiValueOrdinalArray to save on memory consumption
Update README.rst
introduced a new field data loader which is efficient in memory
Fixed ordinal bug
added max_term_docs setting to allow to remove terms with many docs
added a dedicated HashedStringEntry rather then fall back to StringEntry
added the option to exclude by a hash code.