keepalive: handle broken pipes gracefully during large POSTs

diff: add --inverse option Most of the time, one can reverse a diff by swapping the revisions passed with -r but it happens that if you use the global -R, and diff against the tip of the current repo, you can't swap the revisions. One use-case for that is reviewing changes from a bundle before unbundling. One could also pipe the output of `hg diff` to a command line filter that reverses the diff, but that would remove the benefit from color diffs. Therefore, having an option in `hg diff` to reverse a diff is a good thing. The option flag selection was tricky. GNU patch uses -R/--reverse but -R is already used as a global option and --reverse would make --rev ambiguous.

hgweb: keep original order from hgwebdir config files (issue1535)

hgweb: use a tuple-list instead of dictionary for append-only store

templater: readable dates older than 24 months revert to ISO8601 (issue1006)

templater: put 'ago' inside the age template filter

coal/paper: show link to latest file revision (issue1344)

tests: fix hghave test for rst2html to not spew error output

help: describe new cross-branch behavior in update help text, plus cleanups

update: allow branch crossing without -c or -C, with no uncommitted changes Update will now allow crossing branches within the same named branch, when given a specific revision, if the working dir is clean, without requiring the -c or -C option. Abort if no revision is given and this would cross branches. Minor change to abort message if uncommitted changes are found. Modify test-update-branches and output to reflect the altered case. Modify test-merge5.out to reflect the altered case. Modify test-up-local-change.out with new message.

update: add comments and test cases for updating across branches Add comment to merge.py:update() showing various cases of 'hg update': to a descendant, crossing named branches, and crossing branches within a named branch; with no option, -c or -C; with or without uncommitted changes; and with or without a specific revision. Add tests for all of these cases.

patchbomb: fix handling of email addresses with Unicode domains (IDNA) dom.encode('idna') requires dom to be a Unicode string.

clone: add option -u/--updaterev

hgweb/sshserver: extract capabilities for easier modification

kill trailing whitespace