[analyzer] Alpha and implicit checker lists, expand/collapse feature.

The list of alpha and the list of implicit checkers added. An ability to expand/collapse long texts added. Markup fixed.

http://reviews.llvm.org/D3457

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209131 91177308-0d34-0410-b5e6-96231b3b80d8