better file management

I would appreciate the following two functions in the project sidebar:

new file

- create new file from context menu
- instead of opening a new "untitled" file, create a new empty file and focus the filename field to (re)name the file directly after creation

duplicate file

- right click on an existing file
- select duplicate file
- copy the existing file and set the focus on the filename field to rename the duplicated file (w/o selecting suffix)

The suffix thing can be tricky, because there can be multiple suffixes (e.g. .php / .inc.php).