[sldev] Missing OpenAL Library files after trunk update.

[Ambrosia]

Greetings!

Just wanted to let you know, after the trunk update with the new
OpenAL implementation, it seems like the actual OpenAL library files
are missing.

CMake does not grab them, nor are they in the lib package.

See the missing \libraries\include\AL folder/directory. Currently you
will have to grab the openAL source manually.

--Chalice Yao