Moved optflow interfaces and testing app.
Algorithm::info()-related code disabled-after moving to opencv_contrib caused compilation errors

Added usage examples

Added documentation for optflow_io

+bugfix: handling invalid algorithm choice

+ solving MSVC compilation errors; assuming that int and float are 4-bytes long - possibly needs fixing
Moved deepflow to contrib, minor improvements
Deepflow - unfolded loops; faster, terrible code
Added Deepflow to the testing app
Added Deepflow docs
Fixed type conversions (warnings in MSVC)
Merge pull request #68 from tpietruszka/deepflow

Deepflow implementation (and optical flow testing again)