Updates many functions

* removes irrelevant logic used to check some arguments
* changes return value and temporary value variable names (personal preference)
* updates register names
* Removes the part of functions that set the kx13x to sleep where that was needed - it adds a lot more write and reads when they may not be needed. Instead the user will just sleep the device and then change settings - then wake it back up.
* Adds functions for specific interrupt configurations
* Adds functions for initiating various engines
* Adds setCommunicationBus functions that enables the use of the bus drivers

Author: edspark