extdiff: add labels, read diff arguments from [merge-tools]
hgtk has been using these same configs since Feb. Users only have to name the
tools they would like to use, ex:
[extdiff]
kdiff3 =
meld =
patchbomb: respect HGPLAIN when piping --test output to PAGER
It makes easy to use `hg email --test` from another tool.
pager: fork and exec pager as parent process
With the pager as the child process instead of the parent process, the
termination of the parent Mercurial process can cause the terminal to return
before the pager exits. Inverting the relationship prevents that issue.
Platforms without fork() will continue to use util.popen().
commit: fix complaint about branch merge creating new heads (
issue2186)
Fix hg heads -r flag documentation
The command arguments are "[-ac] [-r STARTREV] [REV]..."