Update Basque translation
Prefetch the list of fonts for the style editor dialog

On my machine (with ~5000 fonts installed), enumerating the installed
fonts was about 75% of the total construction time of the style editor
dialog.
Load autoloaded automation scripts in parallel
Kill AssDialogue::SetMarginString

It's no longer used anywhere.
Kill AssDialogue::GetMarginString

It didn't actually make the calling code any shorter or simpler.
Fully extract the resolution resampling logic from DialogResample
Fix display of Unicode font names in the fonts collector dialog
Remove pointless wxID_CANCEL binding
Also handle wxID_CANCEL in DialogManager

wxEVT_CLOSE_WINDOW is only triggered from the platform's close buttons,
not cancel buttons/ESC, so modeless dialogs closed in that way were not
getting deleted.
Make GetReverseUnicodePosition less horribly awful
Fix selection preserving in SubsTextEditCtrl::SetTextTo

Calling GetReverseUnicodePosition on the selection positioning after
calling SetText resulted in the conversions between UTF-8 indices and
wxString indices just being a very slow no-op.
Make DialogTranslation::UpdateDisplay a bit less slow
Support reading keyframes files from ffmpeg/avconv
Fix test compilation
Return full paths from aegisub.dialog.open rather than just filenames
Fix some issues with resampling drawings

The X scale/offset was being used for both X and Y coordinates.

Only non-negative integers were supported. xy-VSFilter and libass both
now support non-integer coordinates, and negative coordinates have of
course always been valid. Resampled coordinates are now rounded to
eighth-pixels rather than whole pixels.