Update CMake instructions in the PortAudio Tutorial

[philburk]

We describe using ./configure but CMake is now a good alternative and should be documented.

Document building libraries, examples, tests and MSVC projects.

[RossBencina]

The existing CMake build instructions are here:

http://files.portaudio.com/docs/v19-doxydocs/compile_cmake.html

The source is here if anyone would like to edit it and submit a PR:

https://github.com/PortAudio/portaudio/blob/master/doc/src/tutorial/compile_cmake.dox

Off the top of my head one thing that should be covered is how to build shared vs. static lib as I think this has changed.

We should also clean up the build instruction links here to make it clear what build systems we support:

http://files.portaudio.com/docs/v19-doxydocs/tutorial_start.html

[Be-ing]

I'll make a PR soon.

[philburk]

I found that this sequence worked to build the examples and tests:

mkdir cbuild
cd cbuild
cmake -DPA_BUILD_EXAMPLES=ON  -DPA_BUILD_TESTS=ON ..
make
examples/paex_sine

[RossBencina]

Related #486

[RossBencina]

@Be-ing please fix this, it's a P2 and we're getting complaints:

#748

[RossBencina]

I've made PR #951 to update the docs with warnings and annotations about inconsistencies between our docs and CMake

Honestly this is a disgrace. I should not have approved the merge of CMakeLists.txt changes without accompanying updates to the documentation. With this ticket being open for almost 3 years, with no PortAudio CMake developers stepping up to fix it, the obvious conclusion is that CMake is an unsupported build system for PortAudio.

[RossBencina]

Removed @Be-ing as assignee, clearly they have moved on.