Implement filtering for multiple CAN ids

[M4GNV5]

i tried to keep the interface simple for the user, you simply specify a list of CAN ids you are interrested in and the library handles when the hardware does not have enough filter registers.

int MCP2515Class::multiFilter(int *ids, unsigned count)

ref #19

[t-c-o-d-e]

Hi,

is this ever implemented?

Thank you for this beautiful and simple for use library!

[ghost]

@sandeepmistry Do you think this could be merged? I have a requirement to filter for two IDs, currently this does need to be done in the MCU, while with this PR it could be done natively in the CAN controller (if you have enough filter registers).