Merge pull request #47 from anarkiwi/v21

Use IDE 2.1.0

Merge pull request #38 from anarkiwi/v23

more efficient implicit purgecmd.

Merge pull request #32 from anarkiwi/serialinit

need serial init.

Merge pull request #23 from anarkiwi/transp

transparent mode.

Merge pull request #22 from anarkiwi/pthru

Add configuration for transparent mode.

Merge pull request #18 from anarkiwi/ffio

Split MIDI read work between poll and parse.

Merge pull request #17 from anarkiwi/fio

 Don't drain transmit buffer right after MIDI receive activity to avoid a slow I/O direction change

Merge pull request #16 from anarkiwi/fix

status LED

Merge pull request #12 from anarkiwi/msgs

rearrange config messages, allow masking of status messages.

Merge pull request #11 from anarkiwi/reset

Implement reset/version, switch to fixed size commands, enable config of through mode, document