2020-3-3 small update: global duration skipping and import filename-dot fixes

A client reported intro trimming failed for RMVB. Tests showed rmvb could not use direct trimming before transcoding. We added global skipping of a specified duration, and also fixed spaces becoming periods during import and upload.

Features

• One: For formats that cannot be trimmed directly, globally skip a selected duration, then transcode and slice with scrolling text and watermarks efficiently.
• Two: Fixed spaces becoming periods during imports and uploads.