Move cmdtable and reposetup handling out of extensions.py
A new function (extensions.extensions) allows the code that is
interested in those attributes to handle them directly.
This allows some cleanups of extensions.py. Notably, we can
remove the extensions.commandtable hack.
It also makes it easier to add standard extension attributes,
like a "hgwebsetup" function or a "helptable" dict that augments
the data in help.py, etc.
# mq patch on an empty repo
tip: 0
No .hg/branch.cache
tip: 0
No .hg/branch.cache
# some regular revisions
Patch queue now empty
tip: 1
3f910abad313ff802d3a23a7529433872df9b3ae 1
3f910abad313ff802d3a23a7529433872df9b3ae bar
9539f35bdc80732cc9a3f84e46508f1ed1ec8cff foo
# add some mq patches
applying p1
Now at: p1
tip: 2
3f910abad313ff802d3a23a7529433872df9b3ae 1
3f910abad313ff802d3a23a7529433872df9b3ae bar
9539f35bdc80732cc9a3f84e46508f1ed1ec8cff foo
tip: 3
3f910abad313ff802d3a23a7529433872df9b3ae 1
3f910abad313ff802d3a23a7529433872df9b3ae bar
9539f35bdc80732cc9a3f84e46508f1ed1ec8cff foo
branch foo: 3
branch bar: 2
# removing the cache
tip: 3
3f910abad313ff802d3a23a7529433872df9b3ae 1
3f910abad313ff802d3a23a7529433872df9b3ae bar
9539f35bdc80732cc9a3f84e46508f1ed1ec8cff foo
branch foo: 3
branch bar: 2
# importing rev 1 (the cache now ends in one of the patches)
tip: 3
3f910abad313ff802d3a23a7529433872df9b3ae 1
3f910abad313ff802d3a23a7529433872df9b3ae bar
9539f35bdc80732cc9a3f84e46508f1ed1ec8cff foo
branch foo: 3
branch bar: 2
qbase: 1
# detect an invalid cache
Patch queue now empty
applying p0
applying p1
applying p2
Now at: p2
tip: 3
9539f35bdc80732cc9a3f84e46508f1ed1ec8cff 0
9539f35bdc80732cc9a3f84e46508f1ed1ec8cff foo