UPD: ok, m17n partly works. It doesn't work only in Kate on my computer (but works on nearby computer with exactly same configuration). Also there are some side effects in some applications like Thunderbird: if you type symbols in it then Ctrl+Z will revert all symbols one by one (this is not correct behavior).
Offtopic: I really don't understand Ubuntu's team politics. What the reason to rewrite and completely break such a essential functionality as layout switching in "stable" release (and force users to update to this release)?
UPD: ok, m17n partly works. It doesn't work only in Kate on my computer (but works on nearby computer with exactly same configuration). Also there are some side effects in some applications like Thunderbird: if you type symbols in it then Ctrl+Z will revert all symbols one by one (this is not correct behavior).
Offtopic: I really don't understand Ubuntu's team politics. What the reason to rewrite and completely break such a essential functionality as layout switching in "stable" release (and force users to update to this release)?