Add symbol "⊛" (Circled Asterisk Operator)

[poscat0x04]

Unicode version of the <*> operator from the class Applicative in Haskell

[berberman]

I extracted input methods from agda as supporting json format: https://gist.github.com/berberman/ccc9ab561eb0478860356b2043e153a9. However, this plugin currently has display errors when a single label is mapped with multiple body (e.g. frac should match one of ¼½¾⅓⅔⅕⅖⅗⅘⅙⅚⅛⅜⅝⅞⅟), so I discarded those from agda-input.el.

[banacorn]

shameless plug: here's a program I use for extracting keymaps from Agda.