VideoCapture: copy the captured frame, to avoid dangling Mats

Previously, VideoCapture::retrieve would return a Mat that referenced
the internal IplImage. Since the latter is rewritten every time a
frame is captured, it means that if the user captures two frames in a row,
the first frame would reference nothing. Similar if a user captures a frame,
then destroys the VideoCapture instance.

Note that the other branch of the if isn't affected, since flip allocates
a new Mat.
minor refactoring of Android VideoCapture jni code to make it similar to generated one
fixed ocl::Moments test
fixed a bug of haar.
Merge pull request #1728 from apavlenko:refactor_vcap_jni
Merge pull request #1730 from ilya-lavrenov:ocl_kern_warn
Merge pull request #1729 from ilya-lavrenov:ocl_moments
remove whitespace.
ocl: fix testdata for blendLinear
consistency SSE2 and plain versions of convertMaps and remap
OpenCV Version++. OpenCV Manager Version++.
Merge pull request #1732 from alalek:ocl_blendLinear
Merge pull request #1733 from ilya-lavrenov:cv_remap
ocl: corner*: fix memory access in kernels; change error check to relative
Merge pull request #1734 from asmorkalov:android_manager_version_inc
Merge pull request #1731 from perping:2.4_haar
Merge pull request #1736 from alalek:ocl_fix_corner_memory_access
fix crash when path has spaces
The paths are defined properly with an escape "\ " but you cannot have an escape and
quotes when piping (otherwise, escapes are understood as 2 characters).
So just remove the quotes.
Overload detectMultiScale API for ocl::haar.
fixed ocl::cornerHarris, ocl::cornerMinEigenVal and their accuracy tests