The framework is composed of 1 main part and 3 different sub-parts. Each
test is linked to this framework and calls the piglit_cl_framework_run
function.

The main part is in piglit-framework-cl.* files. The header contains
definitions to implement each specific test type. The source file's
piglit_cl_framework_run function is called by each test of any type.
This file then parses program and environment variables, and depending
on test configuration, runs the test on selected platforms and devices.

The other 3 sub-parts are tests types implementations: Custom, API and
Program. Each one is used to create tests that benefit from different
functionality. Here each header file contains definitions to implement
an OpenCL test and each source file handles the specific options used in
test configurtation.

Signed-off-by: Blaž Tomažič <blaz.tomazic@gmail.com>