Added methods for sprite sheets with unequal sides
Supports tiles (sprites) with unequal width/height
Scale x and y independently with addCenteredTile
Merge branch 'not-square'
Revert "Merge branch 'not-square'"

This reverts commit cb667bde283e4a798242e39ad666e8ee0bc0ef5f, reversing
changes made to ed00bb47093f3860b67b3e0201eba0786f35a3f7.
Multi-row animation works!

Created a function supporting multi-row animation and integrated it
into the addCenteredTile function.
Integrated multi-row func. into other tile funcs.

Have not tested it with tile functions besides addCenteredTile.
Merge pull request #11 from jmatthewgriffis/multi-row

Seamless support for multi-row animation