Correct switch handling

Correct handling of pushbutton switch when in SLiM.
Minor refactoring and tidying.

Minor tidying & optimisations

Minor tidying & optimisations.

Fix enumeration bug

Fix enumeration bug from previous release

Add sendMessageNoUpdate and transmit handler methods

Add sendMessageNoUpdate and transmit handler methods

Fix compile error in previous release

printf is not available in all Arduino cores.

Integrate long message changes

Integrate long message changes tested by Fergus.

Bump version number

Bump version number. Forgot to do this for 1.1.28.

CAN ID clash in self-consumed messages fix & sequential long messages

CAN ID clash in self-consumed messages fix & sequential long messages.

Fixes to SPI and long messages

Fixes due to changes in SPI in CBUS2515 and Fergus fixes to long messages

New default manufacturer and module IDs

Use DIY for manufacturer ID