Allow combining circumflex \u0302 for Cyrillic vowels, enabling users to express themselves accurately.
ја сам са̂м = I am alone
ја сам сам = I am am
да = yes
да̂ = give
код = at
ко̂д = code
Similar to #437 for aigo.
This replaces the switch cases in KeyModifier.java with JSON files, one
for each diacritic.
The number of states increases from 6727 to 7377. The apk size slightly
decreases (around 3kb).
