Driver for firing multiple i2c sonars individually

New driver for firing up to six i2c sonars to our pixhawk. Based on how much sonars are detected it choses an appropriate firing scheme to miimise interference. Simply connect the i2c sonars through i2c splitter(s) and make sure they each are assigned the correct i2c adress as noted in the driver. 

Status: Compilation is succesfull and testing has been done with the DIY/PX4Firmware fork, but not yet the master fork.
My point was: Reading from a sonar is *exactly* the same for each sonar, except for setting a different address.

So why do you need to copy & paste the code, if all you change is the address? In general a program should not have similar blocks - whenever they are similar, they should be put into a function. Because if you need to adapt anything here, you would need to adapt it six times and not forget a single occurrence.