Fix MacOS Build

[illegalbyte]

The location of OpenAL frameworks have been moved from system library to be a part of the Xcode Command Line Tools, this was preventing the current (17/01/2021) pip install to fail on current MacOS versions.

See issue 67: #67

[usr-ein]

I've tested this PR on macOs Monterey (12.2.1) with python 3.9.1 and it worked like a charm 👍🏻

[tbenst]

I tried on macOS Monterey with Python 3.8.12 with M1 Pro, and got an error:

> pip install git+https://github.com/illegalbyte/pocketsphinx-python
[...]
deps/sphinxbase/src/libsphinxad/ad_openal.c:43:10: fatal error: 'al.h' file not found
    #include <al.h>

Seems to be a continuation of #28 and #67

[ldaumail]

What should be done exactly with a MacOS Monterey?

Here is my issue:
(MacOS Monterey v12.4)
I am currently trying to follow the steps recommended on #28

I replaced two of these lines with:
#include <OpenAL/al.h>
#include <OpenAL/alc.h>

(as recommended on the issue above)

Though, I still have an error when running: python setup.py install
3 warnings generated.
clang -bundle -undefined dynamic_lookup -arch arm64 -arch x86_64 -Wl,-headerpad,0x1000 build/temp.macosx-10.14-x86_64-cpython-38/deps/sphinxbase/src/libsphinxad/ad_openal.o build/temp.macosx-10.14-x86_64-cpython-38/swig/sphinxbase/ad_openal_wrap.o /System/Library/Frameworks/OpenAL.framework/Versions/A/OpenAL -o build/lib.macosx-10.14-x86_64-cpython-38/sphinxbase/_ad_openal.cpython-38-darwin.so
clang: error: no such file or directory: '/System/Library/Frameworks/OpenAL.framework/Versions/A/OpenAL'
error: command '/usr/bin/clang' failed with exit code 1

EDIT: I solved it with 3a56428
Thanks!