Merge pull request #454 from jxerome/master

Elasticsearch engine rewritten
Fix #444
Fix #467
version 2.1.5
Code formatting
Removed try/catch
Fix #453
2.1.6 release
2.2.0 release
Formatting
Code clean up
Added more tests
Fix #468
version 2.2.1
correction avatar bug in admin page
correction avatar bug in search list
version 2.2.2
correction avatar bug in search list
version 2.2.3
update ehcache