Update docs:

- Some comments in hip_hcc.cpp
 - document hipHostRegister* flags.
 - expand docs on hipHostRegister/Unregister. Use "register" rather than
   "pin" to describe action these take.
 - change required CUDA version to 6 (require unified memory)
 - remake doxygen.

docs/RuntimeAPI/html/search/classes_1.js

@@ -1,7 +1,4 @@
 var searchData=
 [
-  ['hipchannelformatdesc',['hipChannelFormatDesc',['../structhipChannelFormatDesc.html',1,'']]],
-  ['hipdevicearch_5ft',['hipDeviceArch_t',['../structhipDeviceArch__t.html',1,'']]],
-  ['hipdeviceprop_5ft',['hipDeviceProp_t',['../structhipDeviceProp__t.html',1,'']]],
-  ['hipevent_5ft',['hipEvent_t',['../structhipEvent__t.html',1,'']]]
+  ['fakemutex',['FakeMutex',['../classFakeMutex.html',1,'']]]
 ];