Many tests didn't change back from subdirectories at the end of the tests ...
and they don't have to. The missing 'cd ..' could always be added when another
test case is added to the test file.
This change do that tests (99.5%) consistently end up in $TESTDIR where they
started, thus making it simpler to extend them or move them around.
The largefiles extension prevents users from adding a normal file
named 'foo' if there is already a largefile with the same name.
However, there was a loop-hole: when merging, it was possible to bring
in a normal file named 'foo' while also having a '.hglf/foo' file.
This patch fixes this by extending the manifest merge to deal with
these kinds of conflicts. If there is a normal file 'foo' in the
working copy, and the other parent brings in a '.hglf/foo' file, then
the user will be prompted to keep the normal file or the largefile.
Likewise for the symmetric case where a normal file is brought in via
the second parent. The prompt looks like this:
$ hg merge
foo has been turned into a largefile
use (l)argefile or keep as (n)ormal file?
After the merge, either the '.hglf/foo' file or the 'foo' file will
have been deleted. This would cause status to return output like:
$ hg status
M foo
R foo
To fix this, the lfiles_repo.status method is changed so that a
removed normal file isn't shown if there is largefile with the same
name, and vice versa for largefiles.
