Add .powrc and .rvmrc in svn, git and hg ignores

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11764 e93f8b46-1217-0410-a6f0-8f06a7374b81
Update URL when changing tab (#13900).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11765 e93f8b46-1217-0410-a6f0-8f06a7374b81