url: catch UNC paths as yet another Windows special case (issue2808)

treediscovery: always return all remote heads Old discovery only returned incoming heads, not all of them (for changegroupsubset). New discovery must always return all of the remote heads (for getbundle). I failed to properly adjust treediscovery in cb98fed52495 when introducing setdiscovery. The actual observable problem was 'remote: unsynced changes' when trying to push a cset on one named branch to a server with a new cset on another named branch. This scenario is now tested in test-treediscovery.t.

merge with stable

config.sortdict: override clear method Overrides dict.clear. It's not currently used, but was broken for sortdict. Contributed by Stepan Koltsov <yozh@mx1.ru>

patch: fix typo in variable name

merge with stable

help/revsets: revset aliases can be defined on any config file

help/revsets: clean up whitespace between paragraphs

help/config: mention [revsetalias] section

fileset: add missing whitespace around operator

fileset: drop backwards SI size units - the power of 2 ones should be kiB, MiB, etc. - the power of 10 ones (SI standard) should be kB, MB, but we're currently using the industry traditional units elsewhere

remove bogus test copy