- new shell command: mem
- new module: bit (for bit operations)
- removed UARTx, TMRx, SPIx, PWMx constants from the respectives modules, as they only waste memory space. But now the same
modules will return an error (via luaL_error) if an invalid resource ID is used. Note that this does not apply to PIO, since
PIO uses special encodings for ports/pins.
- new methods in pio: port and pin to return the port/pin encoded in a pio value.
