Change keyboard shortcuts so they don't overwrite Polish characters

Shortcuts *ctrl-alt-{a,c,e,l,n,o,s,z,x}* are used to type Polish diacritical letters: *ą,ć,ę,ł,ń,ó,ś,ż,ź*. Now Polish people cannot write *ó* and *ś* letters, so I propose to change Open Folder to *ctrl-alt-F* and Save All to *ctrl-shift-S* instead.