Update SpriteImage to modern standards

Update SpriteImage to modern standards

Includes updating shaders to contain the recent size flexibilities
added to QSGImageParticle, adding documentation, moving shaders
into the source file, and optional interpolation.

Small doc fixes, moving shaders into the source file, and moving the
resources (because there are no longer any shaders there) were applied
to ImageParticle and Turbulence (last user of particles resources).

Change-Id: I5e2f133dc4b96dd05d49e7e983ae630e379fa66f
Reviewed-on: http://codereview.qt-project.org/6303
Sanity-Review: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Martin Jones <martin.jones@nokia.com>