update Portuguese (Brazilian) translation
fix position of dir and file panes of PictureBrowser not saved correctly in some cases
fix dropped image url sometimes don't have a correct file name extension
fix searching multi-dates fields with <= or >=

Searching date fields with <= or >= was done with negative > or < filters,
which worked with single date fields, but not with multi-dates fields like play_history
It now simply uses < or > as a 1 second difference doesn't matter.
Note that searches like >july and >=july still differ as the pattern is interpreted differently
make searches like =5h useful by turning them into 4.5h..5.5h
fix occasional crash when using the suggestion menu of SimpleSearch
add icon fallback for gmb-view-fullscreen