test pruning with config

revgraph: add support for prunning revisions and their ancestors

wix: new GUID for contrib.guid

wix: follow filename changes in mercurial tip

Fix visdiff launch for diff against local (other was a tuple)

gtklib: color._styles is not available in hg <= 1.5
The default branch needs to work with 1.5, so provide a copy of the
_styles dict just in case.

gtklib: adapt color extension's user-adjustable styles

gtklib: move some code
This was badly placed by a merge from stable

Merge with stable

commit: grammar fixes for status texts

hgtk: string.startswith() accepts string tuple

Merge with stable

hgignore: display error message if failed to update .hgignore

thgconfig: decode IOError message when displaying
It can contain non-ASCII characters.

hgignore, thgconfig: use util.atomictempfile to update file
It's robust to write via a temporary file than overwriting the target
file directly.
This fixes #240, #1169 (untruncatable Windows' hidden file), but
as a side effect, hidden attribute is stripped.
I think atomictempfile can be implemented to keep file attributes
on Windows.

settings: handle ImportError of pywintypes correctly
We cannot catch both ImportError and pywintypes.com_error at the same
level, because ImportError means pywintypes is not assigned.

Merge with stable

status, i18n: revert parameterized messages introduced by 56b42d08d603

setup: remove PyQt exludes
these are unneeded and highly surprising to discover when trying
to port to PyQt
Side note: py2exe excludes silently win over includes

runcommand: remove unused assignment to fullargs

serve: fix to re-enable --webdir-conf option
This is a remaining fix of 670fe4b733e0.

visdiff: add $repo $phash1 $phash2 and $chash variables
Users may use these variables in their diffargs and diff3args
configurations to add changeset hashes or the repository name.
Closes #1020

datamine: add 'diff to local' context menu option
Refs #732
The other half of #732 is more difficult, as we do not support multi-selection
in the changeset window. Perhaps this will improve when we switch the repo
explorer to use true multi-selection.

visdiff: drop support for ancestor snapshots
It was an interesting idea; but none of the existing visual diff tools
could use an ancestor version when displaying merge diffs. So I'm removing
the generation of what was a redundant node snapshot. This should make
merge visualizations a bit faster to start.

chunks: reverting back to f46c3ea2f429