[NEXUS-5971] remove use of ExtensionPoint
Remove deprecated index related classes.
Moving compat to depend on core
Tearing down compat

Leaving events only for now
Merge remote-tracking branch 'origin/NEXUS-5971-remove-managed-extensionpoint' into remove-deprecated-classes
Events redirected.

This change affects only EventInspectors! All the other EventBus users
subscribers are still safe
Remove deprecated classes.
Remove nexus-compat module
NEXUS-6102: Ditch mimeUtil2, use Tika
NEXUS-6109: Added new method for better precision.

Typically, JAR files are actually ZIP containers, and
Tika will recognize it as ZIP, but we did "reroute" MimeUtil2
and was showing application/java-archive in those cases.

So, a new method helps Tika guess better, as it is able to
use not only content, but also the file name to fine tune
the guesswork.
Moving /content to plugin
Merge branch 'master' into NEXUS-6093-content-plugin
[NEXUS-6093] move templates to plugin
[NEXUS-6093] move content stylesheet
[NEXUS-6093] restlet1x still has its fingers into content stuff
[NEXUS-6093] refactor filter configuration to avoid needing defer
checkpoint simplification of guice configuration of security components to avoid defer()
[NEXUS-6027] kill OperationMode
throw propagate()
[NEXUS-6027] remove getUrlSnippet()