Hello everybody.
I'm just starting to use this newest version of concrete5 - 5.7, and im a little confused with it's new face :)

The problem for me is that in previous version there was a pritty easy way of extending a theme which was provided with package. If I wanted to add my own .css or .js file I could do this in two ways. Both required creating a folder in main 'themes' folder, which had to have the same name as the theme from package. And now:
1. I had to copy the header.php file from the package's theme folder, and put there proper <link... or <script... tags, and after clearing the cache header.php file was overriden with mine, or
2. Just create in such folder - using the same folders structure like in the package - a file with the same name like one which I wanted to override. After clearing the cache the magic was done.

BUT - now in new concrete5 5.7 it doesnt work. Well files overriding works, but when in main folder 'applications/themes' I create folder with the same name like theme from package and place there some file from this theme to override it, then concrete5 starts to behave very strangely. Yes, It overrides the file which I copied to 'applications/theme/package_theme' folder, but stops to take any settings and content from the original package theme. Also I cannot edit the page content because there disappears a posibility of clicking any content element.

I didn't find in documentation any information about extending existing themes in such way, so I'm writing about this on forum, to ask if in new concrete5 it actually possible and if so ... then how :)

Or maybe just someone could push me into right direction...