Provide an implementation of drawFastVLine that is really fast when not rotated.

If any rotations have occured, speed drops drastically.  Should handle 180 degree flip better.
Add support for improving speed of 180 degree drawFastVLine calls.
Add support for rotation in both drawFastVLine and drawFastHLine, including converting drawFastVLine calls to drawFastHLine and vice versa when rotation is 90 or 270 degrees.
Make the code ~30% faster.
switching back to 64 row led for tsting
Merge remote branch 'upstream/master'
Merge pull request #10 from focalintent/master

Improve performance of SSD1306 drawing