NEXUS-5472: Getting rid of signature exc

No need for these exceptions
NEXUS-5472: Javadoc fix
NEXUS-5472: Wrong HTTP code condition

Fixing excepted status codes.
NEXUS-5472: Cumulative fixes

After chat with Igor:
* NFC will not get entries rejected by WL
* Killed GZ file (from spec and implementation)
* index page scrapes resulting in 0 entries considered as failure
NEXUS-5472: Getting rid of WLConfig.getWLMatchingDepth()

Using all we have in prefix file, but also impossibly
huge prefix files (Central has 6k) having over 10k
lines are simply refused to be loaded.
NEXUS-5472: Moved maxEntryCount into config

Along with other feature configurations.