Moved cmd:python3 to TEST_REQUIRES, as even if it seems like the
build needs it (for "summary tests"), it actually doesn't, and its
only for "make test" we need Python3.
Added $jobArgs, as that speeds up the build quite a lot.
Testes passed 100% with or without that set, in any case.
* opencascade: switch to the official version (version 7.7.0)
* completely rewrite the recipe and the patchset
* add all supported libraries and optional dependencies that are available
* tools (command line only) and samples are provided as subpackages
* Tk (and therefore the GUI for DRAW) is not enabled because it hangs on my system
* Xlibe is used to provide a window system
* using both Tk and Xlibe at once is currently not possible due to #7501
* the patchset contains a commit with a stub allowing at least to build without Xlibe, but there is no proper Haiku implementation of it yet. That code path is currently not used.
* EGL is used as OpenGL API, but it doesn't work currently. It displays the following error message:
```
Error: EGL does not provide compatible configurations
```
Test report:
* there are 21000 test cases, so the tests take a while to run
* most tests are skipped due to missing test data (am I missing something how to invoke the tests?)
* the tests involving the Inspector crash into the Debugger because both Xlibe and Qt5 try to create a BApplication when running the Inspector from DRAW (see threedeyes/qthaikuplugins#27)
* some tests hang, pegging one core (although they should have a timeout apparently), they must be aborted manually by killing the secondary DRAWEXE
* the detailed test results are created in $sourceDir/build/results, that folder has 168 MiB zipped
* opencascade: add patch from Liguros to fix finding Qt5 on x86
* opencascade: disable OpenGL, reorganize the patchset a bit
Tools and samples which tried to use OpenGL before will now crash because there is no 3D viewer driver implementation.
