- Have user-history based bigrams used as soon as they are entered,
not after 6 times.
- Limit bigram frequency to 255 (this limits the multiplier to 1.8, and
has no effect on main dict bigrams which already have this limit)
- Some TODO resolving
bug: 4192129
Change-Id: I4777f1a58c43dd55381c4b01252d722ab3a70547