New module dependencies.
New onlp_sys_platform_manage_*() interfaces.

onlp_sys_platform_manage_now()
------------------------------
This function performs any pending platform management tasks through a combination of common code and
the platform-provided onlp_sysi_platform_manage_* functions.

Platform management functions are scheduled through a timer wheel for different frequencies depending upon
context. onlp_sys_platform_manage_now() will call all management handlers who's execution deadline has expired.

This function does not block except in the course of execution of the individual platform management handlers.

onlp_sys_platform_manage_start()/stop()
---------------------------------------
This function manages a separate thread which calls onlp_sys_platform_manage_now() at required intervals to
maintain the current platform asyncronously.

start() -- Starts the management thread.
stop() -- Stops the management thread.
Hack in option to run the platform manager.
- This tool should probably be changed from onlpdump to just "onlptool [dump|manage|...]" etc.
Start global API lock support.
Merge pull request #3 from carlroth/master

Support additional SFP/QSFP modules.
Add onlp_sys_ioctl() public interface.
Merge pull request #4 from carlroth/master

Add support for Dell/Amphenol 3M DAC, see PAN-1057
Merge pull request #5 from carlroth/master

Oops, edited the wrong file
Make macros public.
Increase runtime.
- Handle expired deadlines properly.
- Handle return values from select() properly.