Removed the half-pixel bounding box shift

Shifting the bounding box out by half a pixel in all directions was
implemented to make sure that neighboring tiles  would have the same
elevation values. WCS 1.1, however, samples at the edges of the bounding
box, so shifting the bounding box will produce values that don't match
up.

This change was done to fix the elevation inconsistencies observed when
running osgEarth against the Luciad Fusion map server.
Accidentally removed the update to FindLibNoise.cmake
Merge pull request #438 from ifad-ts/wcs-bounds

WCS 1.1 bounds