Prevent rotation of cell is start or goal.
Made background of cells dark gray and borders darker gray. Reduced border size.
Fixed an oops in preventing player from rotating start and goal.
I keep oopsing. Now, the cell will rotate when you touch it /only/ when it’s not the goal and not the start.
Added five 5x5 levels of increasing difficulty to the grids text file.
Merge pull request #14 from zsweedyk/feature-pipeBorderTouchDisable

Aesthetic improvement and disabling of rotating start/goal
Added app icon imageset and set bundle display name to "Pipe Dream".
Merge pull request #15 from zsweedyk/feature-level-addition

Added five 5x5 levels of increasing difficulty to the grids text file.
Merge pull request #16 from zsweedyk/feature-appicon

Added app icon imageset and set bundle display name to "Pipe Dream".
Fixing merge conflicts in grid txt file