mercurial.el, mq.el: remove runtime dependencies on CL package
* (require 'cl) at compile-time
* don't use map()
% should fail
abort: path contains illegal component: .hg/00changelog.i
adding a/a
% should fail
abort: path 'b/b' traverses symbolic link 'b'
% should succeed
% should still fail - maybe
abort: path 'b/b' traverses symbolic link 'b'