Also, fix the header comments for tidy/w3 so they have the right filenames
Previously the 2 checkers were in the same file - this is more "tidy" (lol??). Currently the logic to determine which checker is loaded is custom to the checker. At some point the SyntasticLoadChecker() function should be upgraded to be able to handle cases (like this one) where the name of the checker doesnt imply the name(s) of the executables that have to be checked for.
The logic for this option was reversed in 2 places. Puppet-lint should have been getting disabled for old versions and if it wasnt installed, but the logic was wrong.
The location list returned by getloclist() may contain entries that are not errorformat matches. By "definition", (see :help getqflist), matched lines have the attribute "valid": 1 set, so only keep those lines in error/warning list to avoid erroneous counts and strange behaviors. Signed-off-by: Florent Bruneau <firstname.lastname@example.org>
The output of flake8 is ambiguous as to whether results should be interpreted as warnings or errors. I have changed it to assume errors to match the python/pyflakes checker. In future we may want to change this or add items to the errorformat for some specific warnings if they are annoying. This fixes #203.