Opening the Level Editor while on title screen or pause menu crashes the page

[ClementSparrow]

Thanks to Tetramouse for the bug report.

[ClementSparrow]

Reopening because I prevented the crash but now it makes nothing when we attempt to open the level editor on the title screen or pause menu. The correct behavior should be:

• pause menu: escape the menu and skip the text messages to the next level or last level, and edit that level
• title screen: if called from pause menu, come back to pause menu and do as stated above? Otherwise, load first level in the editor or a blank level if there is no level.