LSS Zone 1.2.1 alpha 5

- this version now works in SU2014 (force_encoding added where file
system methods calls take place), but fails to work in previous versions
- filter dialog works in SU2014 (force_encoding added for string filter
conditions)
- contour tracing now has one more special case handling: it processes
contours made of instances of the same component definition (or the same
group copies)
- properties dialog now deletes attribute dictionaries more stable
(additional check added to batch properties applying method so it became
stable in case if not only zone objects in a current selection set)
- eye-droppers in the main tool now pick visible material (tool checks
if front surface or back surface of a face is under cursor and returns
face.material or face.back_material depended on check result)
- small bug appeared in SU2014 or maybe in ruby 2.0: it is not possible
to concatenate string value with float value, so 'to_s' method added to
summary_text in a main LSS Zone tool