subrepo: add _relpath field to centralize subrelpath logic
This patch adds propertycache-ed "_relpath" field to
"abstractsubrepo", to centralize "subrelpath" logic into it.
Now, "subrelpath()" can always return "_relpath" field of the
specified subrepo object, because it is ensured that subrepo object
has it. To reduce changes in this patch, "subrelpath()" itself is
still kept, even though it seems to be redundant.
This is also a part of eliminating "os.path.*" API invocations for
"Windows UTF-8 Plan".
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing:
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.