Add support for transferring uint8_t as bytes...

 - Add support for transferring `uint8_t` as a string of bytes.  This improves
   performance slightly, since the values do not need to be packed by `nanopb`.
 - Add `write_uint8(address, array)` to write a string of bytes to the
   specified memory address.
  - __NB__ The size of the array to write is limited by the size of:
   - The packet buffer.
   - The command processor array buffer.
  - The current limit is ~40 bytes.
[NB] Remove site_scons, use `arduino_scons`

 - Remove `site_scons`.
 - Use [`arduino_scons`][1] instead.

[1]: https://github.com/wheeler-microfluidics/arduino-scons/tree/master/arduino_scons
[NB] Add remote _(i.e., i2c)_ board class