The mrclay/minify extension does not work correctly with relative paths, in particular those with ../ or ./. A separate function has been written that prepares paths based on the future location of the compiled file.

The natxet/cssmin extension does not correctly process already minified CSS code. Replaced with matthiasmullie/minify extension.

Fix skeeks-semenov#43

The mrclay/minify extension did not handle relative paths correctly, in particular those with ../ and ./. It has written its own function that adjusts paths based on the initial location of the file and the final one.

The natxet/cssmin extension does not correctly process already minified code, so it was replaced with the matthiasmullie/minify extension.

Fix skeeks-semenov#43