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.
adding base
abort: qdelete requires at least one revision or patch name
abort: cannot delete applied patch c
Now at: b
a
b
a
b
series
status
Now at: a
a
b
series
status
1 [mq]: a
0 base
abort: cannot delete revision 3 above applied patches
f
4 [mq]: f
3 [mq]: e
2 [mq]: d
1 [mq]: a
0 base