revlog._addrevision(): allow text argument to be None, build it lazily

changegroupsubset: use readdelta() fast path when delta is against a parent

run-tests: handle .tst not ending with an LF

minirst: small code cleanup

cat: fix cat without -r, broken by 0ae35296fbf4 The default revision for revsingle() is now '.' instead of None. This preserves the behavior of cat prior to it using revsingle().

revsets: introduce revsingle helper revsingle returns a context for the last revision of the supplied revspec

revsets: make revpair revsets-aware revpair returns the first and last members of the computed revset(s)

revset: lower precedence of minus infix (issue2361)

merge with stable

revset: fix #branch in urls for outgoing() hg log -r 'outgoing(..)' ignored #branch in some cases. This patch fixes it. The cases where it misbehaved are now covered by the added test-revset-outgoing.t