Big Rewrite

I really need to get better about splitting these up.
Get Option now returns a payload pointer when options exhausted.
Update POSIX client for new API.
Fix Validate Return
Go Back to Functions

This was needed because bit fields are too platform dependant.
(Endianness)
Forgot the mid getter.
Update POSIX Example Too (again).
Get MID from right bytes.
Better printing in POSIX example.
MID Getter Fix
Token Getters Fix and Tests
Return Payload Pointer From coap_get_option When No Options
Pass Proper Buffer Size to recvfrom in POSIX Example
Payload now Called Payload
Remove Dead Code in POSIX Example
added function to get specfic option
added observe option number
added ignore file