patchbomb: respect HGPLAIN when piping --test output to PAGER
It makes easy to use `hg email --test` from another tool.
#!/bin/sh
echo % initialize remote repo with branches
hg init remote
cd remote
echo a > a
hg ci -Ama
hg branch br
hg ci -Amb
echo c > c
hg ci -Amc
hg log
cd ..
echo % try cloning -r branch
hg clone -rbr remote local1
hg -R local1 parents
echo % try cloning -rother clone#branch
hg clone -r0 remote#br local2
hg -R local2 parents
echo % try cloning -r1 clone#branch
hg clone -r1 remote#br local3
hg -R local3 parents