largefiles: optimize performance of status on largefiles repos (issue3136)

Describe all files related to the standard commands.

branch: warn on branching

bookmarks: mark divergent bookmarks with book@pathalias when source in [paths]

bookmarks: shadow divergent bookmarks of foo with foo@n

help: properly underline annotate config heading

merge with stable

branch: move note about permanence to the top, add 'global'

util: fix url.__str__() for windows file URLs Before: >>> str(url('file:///c:/tmp/foo/bar')) 'file:c%3C/tmp/foo/bar' After: >>> str(url('file:///c:/tmp/foo/bar')) 'file:///c%3C/tmp/foo/bar' The previous behaviour had no effect on mercurial itself (clone command for instance) because we fortunately called .localpath() on the parsed URL. hgsubversion was not so lucky and cloning a local subversion repository on Windows no longer worked on the default branch (it works on stable because de7e2fba4326 defeats the hasdriveletter() test in url class). I do not know if the %3C is correct or not but svn accepts file:// URLs containing it. Mads fixed it in de7e2fba4326, so we can always backport should the need arise.

convert: tolerate trailing spaces on map files A convert run with a branchmap made with echo default namedbranch > branchmap on Windows fails silently and surprisingly; it actually adds a space after 'namedbranch', so it ends up mapping "default namedbranch" to "". This also affects splicemaps, since the same parser is used for both.