many updates in these days: hoping not boring you too much

The last update of the application is available as usually from http://sr3dbuilder.altervista.org/
It does not contains many news, but just a few but necessaries fixes.
The only significant new is the ability for unregistered users to try the STICKER feature by adding up to 2 sticker to their models.
Loading model with more sticker will causes only first 2 sticker being displayed.
Following the list of what is changed.
Enjoy
Sergio
0.7.3.17 - Changes to previous version (2012.08.29)
Fixed
- Parts with a filename ending with 'H' were not displayed at all
- Connection snapping prevents some parts to correctly align
- Studs connected to a transparent part were incorrectly hidden by the application
- Modifying a Flex do not updates its boundaries box causing problems in reselecting it
Changed
- Unregistered users can add up to two stickers to model to evaluate program feature
- Selecting parts should now be a bit faster due to code optimization
- Updated tire manager association