lib: make rendercopy.h an internal header

And move the public interfaces into intel_batchbuffer.[hc].

A bit messy since we are fairly inconsistent with our header #include
handling.

Also exclude rendercopy.h from the documentation.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

tests/gem_ringfill.c

@@ -43,10 +43,10 @@
 
 #include "drm.h"
 #include "i915_drm.h"
+#include "drmtest.h"
 #include "intel_bufmgr.h"
 #include "intel_batchbuffer.h"
 #include "intel_gpu_tools.h"
-#include "rendercopy.h"
 
 struct bo {
 	const char *ring;