correct return code
split the api into seperate files
find out opencl version
conditionally loads the api calls dependant on the maximum OpenCL version

- removes macros ocl_func_1_x
- changes macro ocl_func to eval in modul context
- import macro in each conitionally loaded file
deprecation not working
reorder api functions
add min macros
use a macro to include the api code, so that you don't have to import the ocl_func macro
removes superflous macros
pull in
move parse_version to api
include platfforms.jl and simplfies __init__
__init__() is only supported for julia v0.3-