hgmerge: fix diff+patch detection; cleanups Details: - actually show help message when no tools are found - whitespace cleanup (stupid emacs) - quote more variables - simplify merge/diff3 error handling

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m "test" -d "0 0"
hg verify
hg parents
hg status
hg undo
hg verify
hg parents
hg status