Add support for "repeated start" as defined by I2C protocol.

[Andy4495]

Library currently does not contain high-level support for "repeated start" signaling.

[Andy4495]

In the six routines that send a stopBit() at the end, add an optional last parameter type bool for repeated_start where the default is false. Check repeated_start: If false, call stopBit(), if true do nothing (i.e., don't send stopBit()).

[Andy4495]

Update from previous comment: There are a total of nine methods that need to be updated. Also, in order to keep the behavior similar to the Arduino Wire library, use an optional parameter called stop_bit which defaults to true, which is the normal case where a stop bit is sent at the end of the message and releases the bus. If stop_bit is set to false then don't send a stop bit, which keeps the controller active on the bus.