Rewrote tilt line to deal with any size line

The initial implementation of tilt line was to test for a length of 4 only.
Rewrote tilt line to handle any length line
Modified tilt line function to combine values on line of any length
Fixed tilt function

Tilt function was causing values to shift when they shouldn't have, fixed
All line tilting tests passed
Added board tilt test
Added calls to board tilt test
Fixed board rotate test to use board_create function

The board tilt test was allocating its own board. A function exists to do this, so using this instead.
Also commented out verbose response from test (not working).
Extended board tilt test cases