disable useless interrupts
receive data that is still in FIFO at RX complete

Fix bad header definition that prevented the driver for working at all. START_IMMEDIATE was actually asking to wait for expiration of the wake up timer, which requires enabling the 32 kHz low power oscillator, which just does not exist on the RFM26W, so the wake up timer was NEVER expiring

Also redefine GPIOs even after WDS canned config.
Also enable more ints.

add success checks in packet handler config
enable pullups on gpios
add code to customize irq enabling
setup rx_start to go back to rx on rx timeout.
display more int status

lots of small misc changes
conditional storage of int status
custom irq setting
cut long lines and add {}
add bit definitions for int definition
upper half: manage read timeout

properly set the data rate
preliminary tx power setting, uncalibrated
TX_NCO_MODE definitions
support for CW modulation (module behave as a signal generator)

Reformat some code