templatekw: change {file_copies} behaviour, add {file_copies_switch}
{file_copies} template now displays file copies with or without the --copies
switch being set. A new {file_copies_switch} template implements the former
behaviour.
#!/bin/sh
hg init test
cd test
echo foo > a
hg ci -Ama
hg up -r0000
echo bar > a
echo % should issue warning
hg ci -Amb
hg up -r0000
echo stuffy > a
echo % should not issue warning
hg ci -q -Amc
hg up -r0000
echo crap > a
hg branch testing
echo % should not issue warning
hg ci -q -Amd