Renderer: Don't sort z=0 Commands

If Command has z==0, then those elements won't be sorted.
Only Z !=0 will be sorted, and it will use `sort` instead of `stable_sort`
for z!=0, since it is faster
Merge pull request #5120 from ricardoquesada/renderer_no_sort_z_0

Renderer: Don't sort z=0 Commands
When android project build native, using multiple concurrent job processes;
android项目编译时,默认利用"-j"参数,启用跟cpu数相同的多进程编译
GlobalZOrder is used for render priority...

...and not vertexZ

Node::setGlobalZOrder() is used to change that.

Node::setZOrder() -> Node::setLocalZOrder();
GlobalZOrder is used for render priority...

...and not vertexZ

Node::setGlobalZOrder() is used to change that.

Node::setZOrder() -> Node::setLocalZOrder();
Merge branch 'global_z_order' of github.com:ricardoquesada/cocos2d-x into global_z_order

Conflicts:
	CHANGELOG
Merge pull request #5123 from ricardoquesada/global_z_order

GlobalZOrder is used for render priority...
[AUTO] : updating submodule reference to latest autogenerated bindings
Merge pull request #5124 from CocosRobot/updategeneratedsubmodule_1390074821

[AUTO] : updating submodule reference to latest autogenerated bindings
Merge pull request #5121 from liang8305/use_multiple_build_process

When android project build native, using multiple concurrent job process...
[ci skip]
Merge pull request #1 from cocos2d/develop

merge all cocos2d/cocos2d-x