Enable global timer

m7
Merge remote-tracking branch 'origin/djole_m7' into milestone/7
Start refactoring AOS-RPC interface
Merge remote-tracking branch 'origin/djole_m7' into milestone/7

Conflicts:
	lib/omap_timer/timer.c
	usr/init/init.c
	usr/mmchs_driver/main.c
Implement read_file
Start LED process from ELF loaded from SD card
Get rid of ELF_S
Start getting rid of global vars
Refactor AOS-RPC #2
Refactor macros
Cleanup mmchs_drv
Refactor procman in terms of AOS-RPC
Add aos_rpc_init_arg
Bring back shell and friends
Improve read file