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
hg init rep; cd rep
touch empty-file
python -c 'for x in range(10000): print x' > large-file
hg addremove
hg commit -m A
rm large-file empty-file
python -c 'for x in range(10,10000): print x' > another-file
hg addremove -s50
hg commit -m B
echo % comparing two empty files caused ZeroDivisionError in the past
hg update -C 0
rm empty-file
touch another-empty-file
hg addremove -s50
cd ..
hg init rep2; cd rep2
python -c 'for x in range(10000): print x' > large-file
python -c 'for x in range(50): print x' > tiny-file
hg addremove
hg commit -m A
python -c 'for x in range(70): print x' > small-file
rm tiny-file
rm large-file
hg addremove -s50
hg commit -m B
echo % should all fail
hg addremove -s foo
hg addremove -s -1
hg addremove -s 1e6
true