Significantly simplify main.cc, rc.cc

Revamp how runtime configs are used through out codebase.
Unify add_vmessage / add_message
Remove support for ! char as the escap ecommand. (Please complain if you are still using this somehow).
Cleanup stacks before shutdown, avoid triggering valgrin in release mode
New codebase orgnaztion
Merge pull request #212 from sunyc/master

New codebase orgnaztion