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.
On POSIX platforms, the 'add', 'addremove', 'copy' and 'rename' commands now
warn if a file has a name that can't be checked out on Windows.
Example:
$ hg add con.xml
warning: filename contains 'con', which is reserved on Windows: 'con.xml'
$ hg status
A con.xml
The file is added despite the warning.
The warning is ON by default. It can be suppressed by setting the config option
'portablefilenames' in section 'ui' to 'ignore' or 'false':
$ hg --config ui.portablefilenames=ignore add con.xml
$ hg sta
A con.xml
If ui.portablefilenames is set to 'abort', then the command is aborted:
$ hg --config ui.portablefilenames=abort add con.xml
abort: filename contains 'con', which is reserved on Windows: 'con.xml'
On Windows, the ui.portablefilenames config setting is irrelevant and the
command is always aborted if a problematic filename is found.
Without specifying the parent revision of the working copy, users will
update to tip, which is most likely the other head they were trying to
merge, not the revision they were at before the merge.