Changes to ensure that keyup fires when combination consists of multiple modifiers and ends with a modifier key.

This is the start of namespace feature for keybinding. so for example, ctrl+a.name and ctrl+a.name2 could be triggered with same key combination.

If there was a space+c binding for instance, it would fire when c is pressed and not consider space. Now, any key will check to ensure previous keys are still held before firing. If window loses focus, it will clear the arrays that hold the held and released keys.