Fixed #191: New UI in the scan popup, replace 3 separate widgets with the translate box.
Adjust the CSS style for the Scan Popup's translate box.
Minor tweaks to have better Scan Popup UI on Linux
Win-specific: Properly scan right-to-left words in GD window
ScanPopup window header
Retrieve old translations for "Dictionaries..." menu option.
Update Argentinian Spanish translation
Fixed #192: Dynamically adjust the suggestion list in the new UI.
Use the same window flags for the scan window, on Win and Linux.

Previously, the scan popup used Qt::Popup flag on Linux, but this
flag is incompatible with the new translate box UI, esp. the
floating suggestion list, since in the Qt::Popup-styled windows
all the events go to the popup, hence the creation of additional
windows is problematic, and those new windows don't work properly
since they don't receive events.

Without this change, the scrolling of the suggestion list in the
Scan Popup's translate box is impossible.