Added U2 bulk data transfer

U2 now allows for writing and reading arbitrary amount of data.

Fix D5a bug

Added D5a logging

Added logging to the D5a module and the controller module. D5a get_settings now also updates the local voltages and span arrays.

Merge pull request #18 from mtiggelman/lockin

Lockin

S4g fix

Small S4g speed fix, necessary for C1 if module is placed >8 slots away

Fix threading lock issue

Merge pull request #15 from peendebak/master

add option to set the number of dacs

D5a fix & S5i improvement

Fixed jump to -4V from 3.999 and PLL lock problem on S5i.

Smalle merge mistake fixed

Smalle merge mistake fixed