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.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
hg init a
cd a
echo 'base' > base
hg ci -Ambase -d '1 0'
hg qnew a
hg qnew b
hg qnew c
hg qdel
hg qdel c
hg qpop
hg qdel c
hg qseries
ls .hg/patches
hg qpop
hg qdel -k b
ls .hg/patches
hg qdel -r a
hg qapplied
hg log --template '{rev} {desc}\n'
hg qnew d
hg qnew e
hg qnew f
hg qdel -r e
hg qdel -r qbase:e
hg qapplied
hg log --template '{rev} {desc}\n'