* imported meta_server and meta_controller
Merge branch 'master' into add_meta_server
* imported meta_controller
- removed unnecessary header in meta controller
* updated connection to master in MetaController.
Merge branch 'master' into add_meta_server
+ added join_meta_server in master_controller
* fixed inconsistency in meta_controller.cpp
* added join_meta_server function in master_controller
Merge branch 'master' into add_meta_server

Conflicts:
	vsfs/masterd/master_controller.cpp
	vsfs/masterd/master_controller.h
	vsfs/masterd/master_server.cpp
	vsfs/masterd/master_server.h
	vsfs/rpc/vsfs.thrift
Merge branch 'master' into add_meta_server
* updated vobla
* modified according to code review.
* second modification according to code review.
* added two more constructor for meta_controller class.
Merge pull request #25 from vsfs/add_meta_server

Add meta server