Add ProtocolUser for custom system plugins.
Merge branch 'develop' into ForUser

Conflicts:
	plugin/protocols/platform/android/PluginFactory.cpp
	plugin/protocols/proj.android/jni/Android.mk
Merge branch 'develop' into ForUser
Up the minSdkVersion to 9
Update target to android-10 for NDK code
Add -landroid to LOCAL_LDLIBS and LOCAL_EXPORT_LDLIBS
#define LOGD
Native Asset Manager
isFileExist()
getFileData()

 * The async case is NYI
 * include stdlib for abort() when forAsync is true
Remove references to zip file
Do nothing in the case of forAsync
TestCpp for iOS uses libcocos2dx, libCocosDenshion, etc...

...as dependencies, and other minor fixes
Adds mac workspace

for the moment it includes TestCpp.
But Chipmunk, Box2d, cocos2dx, extensions and CocosDenshion are libraries
Like in the iOS project
some fixes

removes deprecated functions from AsssetManager
AssetManager: updated project
HelloCpp: does not depent on box2d, chipmunk, etc.
oops

adds missing file
Merge pull request #2985 from ricardoquesada/mac_workspace

issue #2325: Adds mac workspace. Not finished.
removes Xcode's autogenerated library paths
issue #2305:use c++11 thread instead of pthread for WebSocket.
Merge pull request #2987 from dumganhar/iss2305-std-thread

issue #2305: Using c++11 thread instead of pthread for WebSocket.