tests/test-merge5.out

Improved ui.edit():
- Use descriptive name for temporary file: hg-editor-*.txt
- Don't import tempfile in the method, but use demandload()
- Remove tempfile file even if editor aborts.

removing b
this update spans a branch affecting the following files:
 b
aborting update spanning branches!
(use update -m to merge across branches or -C to lose changes)