fixed database version (should stay the same as in Twidere)
merged copy link implementation and show following only on mentions tab
merged from twidere (42e50f6c74f753fdc8da311d14e674f02f52eb96)
merged highlight search keyword implementation, and fixed twidere issues #192 and #193
improved rate limit error messages (german)
Merge remote-tracking branch 'origin/master'