Add MiFare constants, fix setPollPeriod bugs
Added Auth,Read,Write for MiFare classic
Change Card object to use arrays instead of buffers
Switch getUID to getCard
Remove unneccessary log
include new methods in readme
Adding example for nfc read/write
add descriptive comment
update import syntax
Merge pull request #7 from tessel/es-mifare-classic

Implement MIFARE classic read/write