fix issues in image from URL code
allow user to ignore file warnings
report all the errors
test for audio stream (Firefox only)
empty mime type no longer needed

Originally added to work around an issue with URLs pasted in the
file field in Windows, it now does more harm than good.
SWF now has an official mime type
max image dimensions are now 10000x10000
update CHANGELOG
Release 4chan X v1.7.25.