Fix exception resource leak CID 60712
Optimize HTML tag open regex
Fix exception resource leak CID 60556
Remove unnecessary null check CID 56716
Fixed crash in ts parser - thx Marilson :)
Improve batch convert readability a little bit

Also, force refresh of status label and progress bar at the end of batch
item.
Formatting.

[ci skip]
Comment dead code for now CID 18083
Remove dead code CID 18089
Remove dead code CID 18090
Fix undo race conditions

CID 18096, 18115, 18116, 18137
Properly fix null dereference CID 18147