change default arguments for host/buffer_pitches of rectangular buffer transfers to empty tuple instead of None

Add license headers to C++ files

See merge request !60

Add a Titan V CI job

See merge request !59

Fix CommandQueue logic with iterable queue_properties

See merge request !58

Fix macro call split by #if which confuses Visual Studio 2017 (#247 on Github)

See merge request !57

Allow for passing on-device queues to kernels

See merge request !56

Fix leftover words warning in scan kernel generation

See merge request !55

This fixes the following warning when generating scan kernels:

    leftover words in identifier prefixing: arg_offset_adjustment

Fix all kernels

See merge request !54

Add Pytest/JUnit/Gitlab integration

See merge request !53

MinGW fixes

See merge request !52

On windows the temp file cannot be opened a second time while
it is still opened by python. Close the file in python before
asking the compiler to read it.

See https://docs.python.org/3.7/library/tempfile.html#tempfile.NamedTemporaryFile

Fix wrapper for clCreateProgramWithBuiltinKernels

See merge request !51

Introduce PYOPENCL_STACK_CONTAINER to dispatch VLA/std::vector for opposite compiler needs

See merge request !50

Use std::vector for arrays with non-constant length

See merge request !49