The symlink trick made waf go crazy (deleting source files, getting
tangled up in infinite recursion... I wish I was joking). This means we
still can't build the client API examples in a reasonable way using the
include files of the local repository (instead of globally installed
headers). Not building them at all is better than deleting source files.
Instead, provide some manual instructions how to build each example
(except for the Qt examples, which provide qmake project files).
The examples simple.c and cocoabasic.m can be compiled without
installing libmpv. But also, they didn't use the correct include path
libmpv programs normally use, so they couldn't be built with a properly
installed system-libmpv. That's pretty bad for examples, which are
supposed to show how to use libmpv correctly.
So do some bullshit that symlinks libmpv to a "mpv" include directory
under the build directory. This name-mismatch is a direct consequence of
the bullshit done in 499a6758 (requested in #539 for dumb reasons). (We
don't want to name the client API headers directory "mpv", because that
would be too unspecific, and clashes with having the mpv binary in the
same directory.)
If you have spaces or other "unusual" characters in your paths, the
build will break, because I couldn't find out where waf hides its
function to escape shell parameters (or a way to invoke programs
without involving the shell). Neither does such a thing to be
documented, nor do they seem to have a clear way to do this in
their code.
This also doesn't compile the Qt examples, because everything becomes
even more terrible from there on.