Temperature graph

- update French translation
- store elapsed time since the actual beginning of the print to make ETA non crazy when pausing in the middle of the print
- handle another exception which happens when the printer gets disconnected

Merge fixes added to master into experimental

Modified wildcard for FileDialog to add an choice to show All Files

preview zoom by key

zoom big preview by shift + key

Minor fixes

Made lines starting with $ pass through

Made greetings configurable (no longer just 'start')

Fix some translation strings and update translations