revert: move bulk of revert command from commands to cmdutil
This revision has no functionality change. The code on the original
commands.revert() function has been split. The first part of the
original code, which checks that the command inputs are correct
remains in commands.revert(). The rest of the function, which performs
the actual revert operation has been moved into cmdutil.revert().
The purpose of this change is to make it easier to perform a revert
operation, from other parts of the code. This may be used to implement
reverting of subrepos.
$ echo '[Section]' >> $HGRCPATH
$ echo 'KeY = Case Sensitive' >> $HGRCPATH
$ echo 'key = lower case' >> $HGRCPATH
$ hg showconfig Section
Section.KeY=Case Sensitive
Section.key=lower case