update test-help output after new options.

copy: fix introduced bug.

make description of -n option better.

revert: add -n/--dry-run option

remove: add -n/--dry-run option

copy: add -n/--dry-run option

addremove: add -n/--dry-run option

add: add -n/--dry-run option

debugconfig: allow to print by section and exact item name

Fix diff header (line endings) for failed test output in run-tests.py.

Don't run tests with dots in their name (e.g. test-foo.orig)

revert: better fix for not printing 'reverting' message

revert: check for changes against target rev

pick a non-conflicting module name when loading an extension prefix the module name by 'hgext_' so that it doesn't conflict with any core python module (for example bisect -> hgext_bisect) fix issue271

Fixed 'hg serve --webdir-conf foo' which broke due to split of hgweb.

Further cleanup of ui.py (changeset 74d569332f8b used one-char variable names).