Feature Request: Create new and remove old asset files as option for dump

[MicWit]

When doing an assetic dump, the same file names are used every time you do a dump. This could potentially cause issues if a file is cached and the CSS source has been updated. Would it be possible to compare the code of what is about to be dumped into the file with the code that is already in there and then if it is different, delete the old file and create a new one with a different name?

This would mean that every time you do a dump, every asset that has been modified (the resulting asset, adding comments etc won't make a difference if you are minimizing) would change names and when the browser loads the CSS you would know its loading the new version.

[aik099]

It can be done by using CacheBustingWorker (see https://github.com/kriswallsmith/assetic#cache-busting). This way generated filename would always include hash from compiled content.