Adapted INI file for threading, not locking GUI

- Without the `threading` library, the GUI of DevWare gets locked up and
  we don't see what we're doing during acquisition.
  According to email from Bill@Aptina (Tue, 24 Jun 2014 16:09:17 +0000) we
  should split the acquisition part into its own function.
- Make output more concise and clear
- Harmonize all the rounding to two digits.
- functions for `fijioutput` and `SetExposureTime` now accept (optional)
  input parameters and have proper doc-strings
-
More fail-safetyness

Inform user about the maximally achievable fps and the maximally
readable fps and other niceties.
Running on OS X needs some tests, since this INI file made DevWare crash
on Ivans Macbook Pro.
Threading fully implemented and working

After fiddling much too long I figured out a way to make threading work
in Ivans INI file.
Since we can only have one non-locking thread, I "outsourced" all
terminal output into its own function.
Working around the quirks of doing this took me the better half of
today, but now the INI file works reliably on my Mac, and is saving
images as expected.
The INI file still works under Linux
On both OSs the output to the console is not pretty anymore, we're
spewing much too many lines, but this is a small price to pay for a
working INI file...
Merge branch 'master' of github.com:habi/GlobalDiagnostiX