rename r.js modules because OSX won't like same name, different case files

nexus->Nexus, sonatype->Sonatype
Unwrap r.js modules already using Ext.define syntax
Added xtype and singleton support.
Drop a bit of commented cruft.
Fix requireSuper handling, try to automatically determine when to require parent by default... but still leave it up to the caller to force true or false.
Use Ext.apply to customize prototype instance.
Use local field ref instead of 'this' ref for className
Merge branch 'master' into nexus-5472-proxy404
Fix r.js module dependency
Use Ext.define for RepositoryWLPanel
Hide discovery settings for non-proxy repos
Fix typo
Fix partial field rename
Added message for checkArgument
NEXUS-5472: More scrapers.

Added:
* nginx
* s3 stub
Set default value for discovery interval
Fix discovery settings collapse/expand depending on server setting
Fix collapse/expand of discoveryFieldset, hide published timestamp and link on disabled
Use whitelist URL from REST response
NEXUS-5472: Various fixes

Mostly about logging (at DEBUG level) for easier
debug, and enforcing bit scrapers to be more robust with
regarding escaped paths etc.
NEXUS-5472: More logging

In debug.
NEXUS-5472: More logging

Just to make clear that remote discovery is disabled.
NEXUS-5472: Missing licenses added