docs refactoring
Add props to @andreypopp
v0.3.0-rc1

- complete code refactoring, fix #8

**BREAKING**

- `input` option is now `factory`
- `emptyOption` option is now `nullOption`
- no more "Choose your ..." option in selects
- no more need for `multiple` option, use `t.form.select` with lists of
enums instead
- `i17n` option is now called `transformer`
- horizontal forms must be handled by the style
- custom input now must be functions with signature: `(opts, ctx) ->
React Class`
- optgroup has now a `label` property instead of `group`