While generating Java JNI wrappers package names with an underscore (`_`) character where not properly escaped according to https://docs.oracle.com/javase/8/docs/technotes/guides/jni/spec/design.html#resolving_native_method_names (see also: https://github.com/Itseez/opencv_contrib/issues/652).

This fix replaces all the occurrences of `_` with `_1` resulting in proper JNI method names.

* Adds the main features2d header to the parse list for the generator.
* Removes the manual definition of drawKeypoints and drawMatches since these are now included in the main header.
* Updates the generator to ignore SimpleBlobDetector, FlannBasedMatcher and DescriptorMatcher as these cause conflicts with the generator. This is okay since these were not previously included in the distribution anyway, so no harm is done.

fixing fourcc

Revert of "Merge pull request #4006 from sgjava:opencv-steve" (reverted from commit 47431840)

Revert of "Merge pull request #4014 from sgjava:opencv-sgjava" (reverted from commit 52fa55a7)

   (use "git reset HEAD <file>..." to unstage)

	modified:   highgui/include/opencv2/highgui/highgui_c.h
	modified:   highgui/src/cap_dshow.cpp
	modified:   java/generator/gen_java.py

The correction of the orthographic error in the enumeration constant
CAP_PROP_MONOCROME has been undone.

   (use "git reset HEAD <file>..." to unstage)

	modified:   modules/highgui/include/opencv2/highgui/highgui_c.h
	modified:   modules/highgui/src/cap_dshow.cpp
	modified:   modules/highgui/src/cap_pvapi.cpp
	modified:   modules/java/generator/gen_java.py

Änderungen in der PvAPI hinzugefügt.

   (use "git reset HEAD <file>..." to unstage)

	modified:   modules/java/generator/gen_java.py
	modified:   modules/videoio/include/opencv2/videoio.hpp
	modified:   modules/videoio/include/opencv2/videoio/videoio_c.h
	modified:   modules/videoio/src/cap_dshow.cpp
	modified:   modules/videoio/src/cap_pvapi.cpp

Following changes have been made:
1. Some minor bugs have been removed.
2. In the PvAPI module the option CAP_PROP_MONOCROME has been removed because
   this option does not make sense and causes an error if a color camera is used.
3. Instead the new option CAP_PROP_PVAPI_PIXELFORMAT has been added which allows
   to activate the different pixel formats (color modes) of an AVT camera.
4. Since there were two identical defines
   CAP_PROP_MONOCROME = 19
   CAP_PROP_MONOCHROME = 19
   which were also used in the other module DSHOW, the first one with an orthographic
   error has been removed in favor of the second one.

- wrapper support python3
- added wrapper log
- generating full name for nested namespaces and classes

- fixed lena.png extension
- fixed getTextSize wrapper
- added junit html report generation

- disabled xfeature2d dependency for java wrappers
- fixed java wrappers build after cmake rerun
- disabled opencv_ml tests temporarily
- fixed Imgproc usage in java tests

Epoch is gone; now the version component names in C++ and CMake
are consistent (except REVISION corresponds to PATCH).

Conflicts:
	modules/java/generator/src/cpp/VideoCapture.cpp

New version of Java wrappers' generator uses different wrappers for VideoCapture
on Android and desktop to prevent binary compatibility issues.

Java inlines static finals if they're defined with a constant expression. In
case of version constants we don't want that to happen, since they obviously
change from version to version. If the user substitutes a different OpenCV
jar without recompiling, we want user code to still have relevant values for
the version constants.

This arranges that by turning constant values into function calls, which no
longer count as a constant expression.

Typo breaks debug build for Android platform.

- enable auto-wrap of VideoCapture;
- minor refactoring of generated code templates.

'dst' should be treated as an input arg (epilog not needed)