The Downstep character not rendered on some phones

[mvysny]

Some Android phones cannot render the downstep "ꜜ" character properly. Add a setting to alternatively show one of the following characters instead, all of them are verified to be rendered correctly:

Character 1: ↓
Character 2: ⇂
3: ⇓
4: (square root :-D): √
5: v (a simple plain latin lower-case V )

[mvysny]

Added a setting to Settings / GUI Tuning / Dictionary Entry Screen / Downstep Character. Fixed in Aedict 3.39.11