New text filters

I wanted to add some additional filter logic to smart_trim to remove CSS rules, and image filenames (that may be left behind from embedded images) in textarea (body) fields. So, two new filters, which I plan to code as two separate functions. I won't have time to add user interface control over these filters. They would run all the time, but only do something if an image filename is found, or if <style></style> tags are found in the text. I realize these may be edge cases, but for a particular site they are needed. If anyone else can benefit from these additions, all the better.