ccl_kernel_suggest_worksizes: accept NULL gws
if real_worksize is to be considered the final gws.

Also add additional argument checks.
ccl_kernel_suggest_worksizes: accept NULL kernel
in which case information for determining gws and lws is obtained
exclusively from the device.
Update ccl_prof_calc() doc-comments
to account for for the fact that queue events are garbage
collected when this function is used.
Update kernel argument module documentation
Fix type in CMakeLists.txt doc install section
Add ccl_arg_skip to skip kernel arguments
in methods which accept a variable list of ordered arguments.
Turn some profiling messages to info-level messages
making them less intrusive and not printing by default.
Add buffer/image utility macros to wrap ccl_memobj_enqueue_unmap
Fix documentation-related issues
Add user event test + fix bug in ccl_user_event_new

Fix bug in clCreateUserEvent in OCL stub.
Add event callback test, function ccl_event_set_callback()

Passing with real OCL implementations, OCL stub still does not
support event callbacks.
Add event callback support to OCL stub, event test passes w/ stub
Fix build w/ local OCL headers + fix OCL 1.0 event test build
Add test for the ccl_memobj_set_destructor_callback() function

Testing passing for both real and stub OCL implementations.
Add event name and type test

Passing with real and stub OCL implementations for all OCL
versions.
ccl_kernel_suggest_worksizes: allow user specified max. local ws
Additional tests for context, event, image and program wrappers
Add some more context tests

Fix typo in front page
Improve and optimize event wait list handling functions

These functions now return the given event wait list so they can
be used directly in functions which accept event wait lists.
Update docs reflecting updates in event wait list handling