mq: rename series_guards to seriesguards

mq: rename full_series to fullseries

paper, coal: display diffstat on the changeset page Displayed in a row of the changeset summary table, underneath the list of files. When the page is loaded, only the diff summary is displayed. The full diffstat is only displayed when the [+] link is selected.

web: provide diff summary to the changeset page This is the same message displayed at the end of the "diff --stat" command. For example, "9 files changed, 1651 insertions(+), 2 deletions(-)". The webutil.diffstatgen function allows the diffstat data to be lazily calculated only once and then re-used.

tests: fix up date ambiguity in cvs test

hg: split peer and repo lookup tables

tests: rename test-git-import.t into test-import-git.t This is consistent with other test-import* tests.

patch: generalize the use of patchmeta in applydiff() - Add patchmeta.copy() and emit copies from iterhunks. Modifying patchmeta instances in applydiff() makes things simpler. - Rename selectfile() into makepatchmeta(). It is responsible for creating patchmeta for regular patches. - Pass patchmeta objects to patchfile() directly patchmeta instances were associated with git patches, for regular patches we had to pass additional variables to tell the patch intent to patchfile(). Instead, we generate patchmeta for regular patches and pass them. This will also help with patch filtering by matcher objects.

patch: stop updating changed files set in applydiff() This information is more correctly returned by backends. The extra updated file removed from test-mq-merge.t output came from changes from git patches being counted before being really applied in some cases.

patch: turn patch() touched files dict into a set