Feature/oak index manager

AEM6 Oak Index Manager; implementation for Issue #242.

AEM6 WebUI for viewing indexes and issuing re-index requests.

![oak_index_manager___acs_aem_commons](https://cloud.githubusercontent.com/assets/1451868/3434562/679f5672-008b-11e4-92f0-68d3dc081654.png)

Currently method for "detecting" AEM6 is a little suspect (looks for an /oak:index) in ACS Tools we have the Helper to determine if an Oak repo. Not sure what the best way to share these common elements between projs is.