remove SK_SCALAR_IS_[FLOAT,FIXED] and assume floats

To keep the CL (slightly) managable, this does not make any changes to
existing macros (e.g. SkScalarMul). Just tackling #ifdef constructs this
time around.

BUG=
R=bsalomon@google.com, caryclark@google.com

Review URL: https://codereview.chromium.org/117053002

git-svn-id: http://skia.googlecode.com/svn/trunk@12712 2bbb7eff-a529-9590-31e7-b0007b416f81
69 files changed