[refac] first part of the refactorization that simplifies the asynchronious implementation and prepares xively for cyassl

Conflicts:
	src/libxively/io/posix_asynch_ssl/posix_asynch_ssl_io_layer.c
	src/libxively/io/posix_asynch_ssl/posix_asynch_ssl_io_layer.h
	src/libxively/xively.c
[feature] extended the layer api to be make it possible for layers to init and connect independently
[refac] refactorized the posix layer to use the new init and connect approach
[update] updated the posix_layer to print errno value whenever it fails to connect
[refac] refactorized the posix_asynch to use new init and connect approach
[refac] adjusted the dummy layer to use the separated init and close approach
[refac] adjusted the mbed layer to use the separated init and connect
[fixes] post refactorization fixes
[fix] names of the functions didnt match the actual declaration
[fix] variable initialization
[fix] added missing semicoln
[fix] various fixes about the function names and new flow
[imports] Check-in errordeveloper/mqtt-codec@689b0a9
[imports] Update to errordeveloper/mqtt-codec@7a345ad
[build] Add mqtt-codec sources
Merge pull request #96 from xively/refac_libxively_states_rename

Refactor states names
Merge pull request #95 from xively/feat-mqtt-codec

[imports] Check-in errordeveloper/mqtt-codec@689b0a9