contrib: update tcsh_completion with commands for 1.6
Added the following commands: debugbuilddag debugdag debugpushkey
debugrevspec.
addchangegroup: pass in lock to release it before changegroup hook is called
Currently, callers of addchangegroup first acquire the repository
lock, usually to check that an unbundle request isn't racing. This
means that changegroup hook actions that might write to a repo get
stuck waiting for a lock. Here, we add a new optional lock parameter
and update all the callers. Post-1.6 we may make it non-optional.
cmdutil: only output style header once in non-buffered mode (
issue2130)