Implements the master/detail pattern across the rest of the console
Reduces the size of the header in messages
Fixes spacing in various places throughout the app
removed yum documentation in favour of Nexus book

Conflicts:
	plugins/yum/nexus-yum-repository-plugin/README.md
removing readme altogether as indicated by jdillon
Merge remote-tracking branch 'origin/master' into NEXUS-7292-scheduler-rework