Eliminated getPointers which are memcpyed or memset.

Removes 12 getPointers.
Remove another 3 getPointers.

Thanks neobrain for spotting these.
Revert changes preloading of RGBA8 tiles.

This path should probally be optimised, but it's out of the
scope of this PR.
Merge pull request #1342 from phire/lessGetPointer

Eliminate getPointers which are memcpyed or memset.