smoketest: add script to automate preliminary app testing

./smoketest verifies the integrity of all the lambdanative apps.
Specific apps can be listed on the command line, like so:
./smoketest iControl telePORT myRandmAppHere
In order for an app to pass the test it must 1) build successfully
and 2) after launch either exit without error or survive long
enough (2s) to be killed by the smoke script.