Added API views TARGET_(HOST|SERVICE|ALL)_PROBLEMS

Providing views to view all host, services and a mixed view or every object
that is not OK.

refs #4167
Added Cronks All (Host|Service|) problems

Providing grids to view all host, services and a mixed view of every object
that is not of status OK.

refs #4167
Reduce username length requirement to 2 - drop first/lastname min length

Changed AJAX validation and JS form settings.

refs #3459
Force columnImage to be 16px to avoid too big icon_image for host or service

fixes #2784
Changelog and version information for 1.9.2
Merge branch 'master' into next

Conflicts:
	configure
	doc/VERSION
	etc/make/version.m4
	icinga-web.spec
Merge branch 'feature/problem-cronks-4167' into next
Merge branch 'feature/reduce-name-length-3459' into next