scmutil: improve documentation of revset APIs I can never remember the differences between the various revset APIs. I can never remember that scmutil.revrange() is the one I want to use from user-facing commands. Add some documentation to clarify this. While we're here, the argument name for revrange() is changed to "specs" because that's what it actually is.

mdiff: remove use of __slots__ The use of __slots__ was added way back in 2006 in 4ec58b157265. __slots__ isn't necessary for this class.

i18n: use unicode literal Other parts of this expression are already using unicode literals. We need this to make Python 3 happy and to avoid an implicit conversion in Python 2.

pycompat: add HTTPPasswordMgrWithDefaultRealm to Python 3 block Looks like we missed this in 800ec7c048b0.

ui: path option to declare which revisions to push by default Now that we have a mechanism for declaring path sub-options, we can start to pile on features! Many power users have expressed frustration that bare `hg push` attempts to push all local revisions to the remote. This patch introduces the "pushrev" path sub-option to control which revisions are pushed when no "-r" argument is specified. The value of this sub-option is a revset, naturally. A future feature addition could potentially introduce a "pushnames" sub-options that declares the list of names (branches, bookmarks, topics, etc) to push by default. The entire "what to push by default" feature should probably be considered before this patch lands.

ui: don't fixup [paths] sub-options As part of developing a subsequent patch I discovered that sub-option values like "." were getting converted to paths. This is because the [paths] section is treated specially during config loading. This patch prevents post-processing sub-options from the [paths] section.