tests/test-merge3

Pass correct username as $HGUSER to hgeditor if "commit -u" is used.
And only use the new util.system parameter to set the environment.

#!/bin/sh

hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
touch b
hg add b
rm b
hg commit -A -m"comment #1" -d "1000000 0"