[utils] deblankString: funtion to remove blanks from strings
[test] Test for util::deblankString
Property::unit(str): Deblank string before unit checks

A well-known recording software uses e.g. " kHz". Let's work with
that.
Merge pull request #210 from gicmo/deblankUnits

Remove blanks form unit strings in Property::unit(str)

lgtm