Various documentation updates in preparation for the 2.1.0 release.
Final documentation updates before release 2.1.0.
Commented out some function arguments in test programs to avoid compiler warnings.
Removed Windows kernel streaming code because it was incomplete and uncompilable.  The code still exists in the winks branch.
Deleted include directory with kernel streaming files.
Removed another reference to kernel streaming support in readme.
Removed reference to WINKS in midiprobe.cpp
Corrected documentation regarding API default order in RtMidi.h
Revert "Removed reference to WINKS in midiprobe.cpp"

This reverts commit 774c66488cf9e2a1de119feb72529a0b144f4d08.
Revert "Removed another reference to kernel streaming support in readme."

This reverts commit 745fbe3fa6aa313b4e9d40cce465e57d07111afc.
Revert "Deleted include directory with kernel streaming files."

This reverts commit 290db6cd3ead705fd117a72d589426d22ba23f8e.
Revert "Removed Windows kernel streaming code because it was incomplete and uncompilable.  The code still exists in the winks branch."

This reverts commit d07f6011cfdb3ba59cbd409b7005d5676cdca4d4.
Partially define an API for reliable port selection.
Mark RtMidi.h to be C++.

This helps certain editors to select the correct mode
that usually interpet .h files as C headers.
Merge port Id type into PortDescriptor and go further with cascading the API.
Complete the API part of the new PortDescriptor based API

This includes also some reorganisation that moves the common global/local
API out of RtMIDI and the backend api.
Revert renaming MidiApi into MidiBackendApi and rename the other MidiApi.

The new MidiApi is now called CommonMidiApi.
This avoids some compilation errors.
Fix some compiler errros.
Add missing inline functions and reformat existing ones.

This should be better readable.
Namespace based API and get rid of virtual inline functions for RtMidi(In|Out).

This patch includes more than it was intended to. The changes include:
• provide a namespace rtmidi to simplify class names
• Make all functions of Midi(In|Out)? non-virtual.
  Virtual inline functions have several pitfalls.
• provide Dummies for the new ALSA api.
• provide workaround for the major API breaks.
• use references for passing certain pointer arguments and deprecate
  the pointer versions of these functions.