Corrected synopsis of hg heads

Test that we notice the empty files from the second parent during a merge This didn't work with 0.9.1, but was fixed by 05257fd28591.

revlog.py: always return tuples from parents and parentrevs There's at least one place doing parentrevs(rev) != (rev-1, -1), which is always true with revlog v0, since parentrevs returns a list in this case.

Some README updates

Remove some old documentation that belongs on the wiki

Move rewrite-log to contrib

Remove [-b] options from help syntax lines

Deprecate old --branch/branches options

add branch and branches commands

test-mq-caches: look up a revision that does not exist to force cache creation

Merge with mpm

hgweb: add heads to gitweb summary

zsh: cache hg help output

zsh: complete according to the -R option if specified

zsh: add view opts

zsh: add --style and --template opts

zsh: add -r to parents

zsh: expand tags lazily

make mq play nicely with the branch cache - if no patches are applied, don't do anything different - if the cache includes valid data from one of the patch revisions, use the cache, but don't save anything new - if the cache has data from before the patch revisions only, save what the list of branches would be without the patch revisions

Split branchtags into two additional functions. This makes it easier to override only parts of the cache saving process.

Merge with crew

Commit username: Better error message, abort on empty name, fix documentation.

hgweb: make #motd# available for all templates

zsh completion: basic mq support

bash_completion: qguard

bash_completion: allow overriding completion for arguments that start with "-"

bash_completion: qfold, qrename, qheader, qclone and qselect

bash_completion: email --bcc

bash_completion: qdelete --rev

bash_completion: make export fall back to tags when there's no mq patch applied