color: move 'debugcolor' into the 'debugcommands' modules
This is the last bits we needed to move out of the extensions. 'hgext/color.py'
now only contains logic to changes the default color behavior to 'auto'.
However, more cleanups are on the way and we need to document the new config
directly in core.
$ hg init
$ touch a
$ unset HGUSER
$ echo "[ui]" >> .hg/hgrc
$ echo "username= foo" >> .hg/hgrc
$ echo " bar1" >> .hg/hgrc
$ hg ci -Am m
adding a
abort: username 'foo\nbar1' contains a newline
[255]
$ rm .hg/hgrc
$ HGUSER=`(echo foo; echo bar2)` hg ci -Am m
abort: username 'foo\nbar2' contains a newline
[255]
$ hg ci -Am m -u "`(echo foo; echo bar3)`"
transaction abort!
rollback completed
abort: username 'foo\nbar3' contains a newline!
[255]