fix: improves in the ginga input

[RodrigoDornelles]

This is a temporary solution, but the definitive one could be a mix of the current one and this one.

local function event_loop(std, evt)
    if evt.class ~= 'key' then return end
    if not key_bindings[evt.key] then return end
    std.key.frame = 1
    std.key.press[key_bindings[evt.key]] = 1
end

local function install(std, game, application)
    std = std or {}
    std.key.frame = 0
    application.internal.fixed_loop[#application.internal.fixed_loop + 1] = function()
        if std.key.frame == 2 then
            std.key.frame = 0
            std.key.press.up=0
            std.key.press.down=0
            std.key.press.left=0
            std.key.press.right=0
            std.key.press.red=0
            std.key.press.green=0
            std.key.press.yellow=0
            std.key.press.blue=0
            std.key.press.enter=0
            std.key.press.back=0
        end
        std.key.frame = std.key.frame + std.key.frame
    end
    application.internal.event_loop[#application.internal.event_loop + 1] = function (evt)
        event_loop(std, evt)
    end
    return std
end