Clean up SkTypes.h.

Clean up SkTypes.h.

This change removes sk_stdint.h since it is only needed for vs2008 and earlier.
This change removes SK_MMAP_SUPPORT define since it is no longer used.
This change removes the stdio.h include from SkTypes.h since on many systems
this is a very large header, few Skia files actually use it, it is
available everywhere standard, and SkDebugf should be used instead.

After this change there is no need for external users to put Skia's
include/config into their own list of includes, saving the headache
of having two header files of the same name and sometimes getting the
wrong one depending on include order.

R=bsalomon@google.com, djsollen@google.com

Review URL: https://codereview.chromium.org/27044002

git-svn-id: http://skia.googlecode.com/svn/trunk@11738 2bbb7eff-a529-9590-31e7-b0007b416f81