Shimmer GSR change to alg. to convert from adc val

Change to algorithm to convert from raw ADC values to resistance. New conversion uses linear fit and is much more accurate than the (now removed) polynomial fit, especially at the edges of the ranges. Also added a command, smoothTransition(), to eliminate spikes in resistance value at autorange transitions (previous value is maintained until circuitry has settled).
Shimmer GSR changed conductance variable to float

For greater precision
Shimmer Bluetooth driver updates

Allow baudrate to be set to 230400 using preprocessor definition: USE_230400_BAUD
Remove dependency on shimmerMessage.h for sending packets (as was needlessly inefficient for this purpose). Almost doubles max permissible outgoing packet size to 255 bytes.
Shimmer gyro driver update

Default SER0_CTS signal to give gyro signals and no longer modify when starting or stopping (allow higher level app do this as necessary)
Shimmer heart rate driver update

Greatly simplified. Removed unused, inaccurate, functionality. Now the timestamp of when the heart beat is detected is passed to the higher level application rather than trying to determine the beat rate. Remove spurious beats added by some (non-rmcm01) coded sensors.
Shimmer MSP430 I2C bug fix

Change name of I2CDR register to I2CDRB (as former is deprecated in msp430-gcc v4.6.3).
Shimmer mag driver update

- Increase startup delay in Init.init() function from 5ms to 10ms (datasheets says chip takes 8.3ms to startup)
- Fix errors in setGain() command