Filenames for uploaded files with random name generation now will preserve extension when uploading.

[o_z]

Don't know if someone used file uploads with :unique parser but for me they were not usable since on upload files renamed from something like "image-file.jpg" to "AFSDF123" and this caused some problems with mime types (correct headers didn't show) and as a result something didn't work (either images didn't show or there were some bugs with .mp3 files, don't remember now).

Now all is ok, changes are merged into weblocks, please update your code as needed since this fix can brake something in your apps.