Basic AulxUI inheritance structure using my Popup.

W00t! FTWBBQ! Go review this big change now. TTYL!
Remove unused file
Fix some indentations.
Bring back normal navigation when popup is closed

2 things remaining now, code wise :
1. Fix one popup location issue
2. Implement the insert method again.
Fix popup location bug

Now only blocking thing is insert function. Rest everything else would
be additional things.
README fix
Implement insert method \o/

Also adjust popup alignment so that it remains at same horizontal
position while typing things along.
Fix UP/DOWN logic a bit.

Maybe UP/DOWN handling should be removed completely.
Handle left and right to close popup and stop catching up and down.
Documentation.
minor readme change
codemirror character width calculation fix