Add api_add_int16 to API functions.
Use a custom mystrstr function in cointerra driver.
Export the api_add_int16 function.
Convert and update values shown in the cointerra api output.
Make the cointerra displayed hashrate based on valid share generation.
More gracefully break out of parse_notify on a corrupted hex string error, checking the return value of all hex2bin conversions and being consistent with using stack memory. Fix an unlocking error in cases of failure.
Merge pull request #557 from kanoi/master

Ant S1 Driver