Converted Big Foot Burden Quest's action scripts to meta. Added achievement to piggy bank. Fixed playerExists function and some minor changes to Achievements lib.

Added achievement "Allowance Collector" when using 50 piggy banks.
Fixed function playerExists in customfunctions.lua. It was always returning true.
Some minor changes in Achievements Lib.
make variable local instead of global.

Not sure if this should be moved above the function when getPosition is used, @ninjalulz , @TheSumm ?