patchbomb: add a 'bundletype' config under 'patchbomb'
patchbomb relies on the 'hg bundle' command to generate an attached bundle using
--bundle. However, while 'hg bundle' has a --type option, patchbomb did not.
This is becoming very relevant since we are about to issue bundle2 for
general-delta repository.
This was tracked as issue4863
$ 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]