templatekw: allow getlatesttags() to match a specific tag pattern
This will allow the latest class of tag to be found, such as a release candidate
or final build, instead of just the absolute latest. It will be exposed in a
future patch.
It's unfortunate that the original 'latesttags' cache can't be used to determine
the proper values, but it isn't fully populated for the entire repo. For
example, the {latesttagdistance} keyword on the Mecurial repo builds the cache
up back to the revision for 1.4. If the pattern was 're:^0\.\d$', that wouldn't
be in the cache. Maybe this can be optimized some other way, but for now, this
is the simpliest implementation.
% lazy ancestor set for [], stoprev = 0, inclusive = False
membership: []
iteration: []
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = False
membership: [7, 8, 3, 4, 1, 0]
iteration: [3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [1, 3], stoprev = 0, inclusive = False
membership: [1, 0]
iteration: [0, 1]
% lazy ancestor set for [11, 13], stoprev = 0, inclusive = True
membership: [11, 13, 7, 8, 3, 4, 1, 0]
iteration: [11, 13, 3, 7, 8, 1, 4, 0, 2]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = False
membership: [7, 8]
iteration: [7, 8]
% lazy ancestor set for [11, 13], stoprev = 6, inclusive = True
membership: [11, 13, 7, 8]
iteration: [11, 13, 7, 8]