Fixes and improvements to pattern matching

[ViRb3]

This PR adds a bunch of fixes and improvements to the pattern matching algorithm:

• Correct tracking of patLen. We want to count the worst possible size for each expression, previously this was not followed in all cases.
• Lazy evaluate quantifiers (jumps) to match YARA's behavior
• Use single-line flag for regex to fix mathing when new line byte (0xA, \n) is involved
• Track needle offset within the pattern, and when expanding needle results to regex windows, do so by the exact amount in each direction based on this offset
• Check for and return sub-matches, which is unlike regex but YARA does this

Specific examples to some of these cases are inlined as comments.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[stevemk14ebr]

This is a fantastic PR thank you so much! As soon as you sign the CLA I can begin the code review and work towards merge

[stevemk14ebr]

I do not see any issues here, I will do some testing and then cut a release in a few days