Zero volume transfers are not ignored in transfer protocols

[jgruselius]

Description:
The robot performs liquid transfers with 0 µL volume. The parsing function should ignore these. This problem lies in jgr_lib_v130*.js script files.

[jgruselius]

Source of bug:
Numbers are unintentionally converted to strings in the parsing functions when using number.toPrecision(), then the if(volume) statement always returns true and thus 0-volume transfers will not be ignored.

Fix:

var number = Number(valueString);
number = +number.toFixed(nPlaces);