All tests passed!

- added webp (lossy and lossless without alpha channel)
- added tests

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

OpenCV issue #2604

After this patch applied an attempt to encode empty images produces exception
saying "Raw image encoder error: Empty JPEG image (DNL not supported)"

- imdecode_() only creates a temporary file when needed.
- Use the string's empty() function to flag if the temporary file needs
to be deleted.

replaced "const InputArray&" => "InputArray"; made InputArray and OutputArray references. added "None()" constant (no array()).

a big patch; use special proxy types (Input/OutputArray, Input/OutputArrayOfArrays) for passing in vectors, matrices etc.

added workaround for strange tmpnam() output from VS2010. turned off optimization for DCT & DFT on Win64 for VS200x (VS2010 builds it fine)