In the case where there is no error log for arbfp we were returning a
"" string literal. The other paths were using g_strdup to return a
string that could be freed with g_free. This makes the arbfp path return
g_strdup ("") instead.
There are quite a few if {} else {} blocks for dealing with arbfp else
glsl and the first block is guarded with #ifdef HAVE_COGL_GL. In this
case though the #endif was before the else so it wouldn't compile for
gles.
This makes CoglProgram/Shader automatically detect when the user has
given an ARBfp program by checking for "!!ARBfp1.0" at the beginning of
the user's source.
ARBfp local parameters can be set with cogl_program_uniform_float
assuming you pass a @size of 4 (all ARBfp program.local parameters
are vectors of 4 floats).
This doesn't expose ARBfp environment parameters or double precision
local parameters.
