Revise API reference templates to make them compatible

with both DAC and DevSite. Includes a variety of cleanup and redesign.
Now prints method parameters and return values even if not documented in source.
Now prints return value data type.
Now prints method name as heading without arguments, then the full signature below.
New heading styles with more spacing and removed background color.

Change-Id: I7a991df5e8d0d7ac8ff81c20b4b4692e67eb88aa