COMP: Conditionalize insane "#define inline" in libtiff

This was causing mysterious linker errors if building
against the OS X 10.9 SDK.  Limit it to MS compiler,
which does not support 'inline' in C.

Suggested-by: Sean McBride <sean@rogue-research.com>

http://review.source.kitware.com/#/c/12924/3

Change-Id: Ic72f744d0b9b68412d65792ca1430a9151d7080a
Merge topic 'tiff-inline'

08bf6be COMP: Conditionalize insane "#define inline" in libtiff