Added struct af_features to store image features (aka keypoints).
Added features class to manage af_features structs.
Added FAST feature detector frontend.
Added FAST feature detector CPU backend.
Added FAST feature detector CUDA backend.
Added FAST feature detector OpenCL backend.
Use & operator for array in resize definition
Fixes #167: Check if driver is unloaded when freeing array
Merge pull request #170 from umar456/devel

Fixes #167: Check if driver is unloaded when freeing array
Quote user-supplied paths. Search CMAKE_INSTALL_PREFIX last to prefer local installs.
Added handlers for array type in features class.
Fixed failing abs() call for int/unsigned types on CUDA backend of FAST.
Added test reader for image input with array output.
Added FAST unit tests.
Merge remote-tracking branch 'upstream/devel' into fast
Merge pull request #173 from bkloppenborg/FindclFFTImprovements

Improve FindclFFT.cmake
Merge pull request #174 from shehzan10/devel

Pass input as reference to resize function.
Fixed FAST files to comply with new directory structure.
Fixed data filename on FAST unit test.
Updating test/data submodule