cleanup ocl_icd.h
cleanup ocl_icd.h

- add empty lines
- use system headers in #include
- add macro for API version and for number of identified functions
- stabilize the name of all unkown entries by using the entry number
- reformat the struct _cl_icd_dispatch

git-svn-id: 33409ba78411f2a1359a9b73a7b59b6f729a477f@27 54081c91-f12c-4b0d-b4b4-172e8089a626

OCL-dev/ocl-icd,OCL-dev/ocl-icd,OCL-dev/ocl-icd