[analyzer] Open Projects: grammar, phrasing, formatting

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179658 91177308-0d34-0410-b5e6-96231b3b80d8
[analyzer] Merge C++ status page into Open Projects.

Also, add a few random extra open projects.

Most of C++ support is done; we don't need the status page anymore. We're
hoping that the C++-related open projects are the only major pieces of
functionality we don't model at this point.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179659 91177308-0d34-0410-b5e6-96231b3b80d8