Implement barfly testing

[petdance]

In the word branch in ack2, there's an implementation of barfly testing. It needs to:

1. Be callable from a line of code, such as

use Barfly;
barfly_tests( *DATA );

or

use Barfly;
barfly_tests( 't/barfly/ack-w.txt' );

2. Implement the code that does the YESLINES sections, which doesn't work yet. This will rely on the --underline getting implemented.

[petdance]

Implemented the YES and NO sections, but not the YESLINES.

[petdance]

Created a basic syntax/barfly.vim in the dev folder.

[petdance]

YES/NO and YESLINES testing has been implemented in Barfly.pm.

We need to add a .t that verifies that underlining and highlighting matches all the time. Otherwise we can't use YESLINES as a proxy for testing highlighting.

[petdance]

Add more barfly to other tests.

[petdance]

Done. 254a2dd