Rearrange CMakeLists for including C99 stdint

The installation paths needed to be earlier before the try compile so
that they could be used in the C99 sub-directory.

Change-Id: I4336e3a570193d1f76dcaa8e3f306a360c41b980
Importing C99 int header

These file have been obtained as revision r26 from:

  http://code.google.com/p/msinttypes

The files are licensed under BSD-like terms.

Change-Id: If3ce0654d45865efcd375b89b686e5528ad5a314
Include C99 directory when no stdint.h header it found.

These files also get installed into the SimpleITK directory when not
found.

Because this header file is not wrapped, and has the same name as the
system. It makes code cleaner to maintain the expected name. However,
it may cause conflict and incompatibilities if other project follow
the same pattern. The may be a rare occurrence and at the moment does
not appear worth the change.

Change-Id: I40c83cc09f07101a13c99735a5593fbbb39400cb
Merge topic 'SIMPLEITK-350_Include_stdint_VS9' into next

7c5adf5 Include C99 directory when no stdint.h header it found.
394320b Importing C99 int header
d432f9c Rearrange CMakeLists for including C99 stdint