Changes the python lever to classify match and case as keywords if they are in the keywords set and are in a position where they are probably keywords and not identifiers -- at the start of the line and not followed by a '=' or '.'.

There are ambiguous cases where match / case could be a keyword or identifier that are classified as a keyword. This could be resolved by scanning ahead for a terminating ':', but it would require something close to a python tokenizer and the match / case should probably be classified as keywords while the line is being entered. An example are the lines 'match (x)' and 'match (x):' -- match is an identifier in the first, but a keyword in the second.

There are cases where the statement starts on the prior line that aren't handled correctly, but should be rare and would be difficult to fix within the current approach.

I opted not to add an option to control this, but could if someone wants to highlight all match and case symbols as keywords.

Note that match and case were added to python/SciTE.properties for the tests; this doesn't seem to affect the other tests.