EasyRPG-exclusive command "DestroyMapEvent": "ThisEvent" not supported

[florianessl]

Trying to use this new event command to make it possible to "self destroy" a running event will just cause warnings:

This can of course be circumvented by looking up the current event id via the "ControlVariables" command & using the indirect adressing mode of the command, but there are two issues here:

• ControlVariables' branching option Event -> Event ID is only available if Maniac support is enabled. (Otherwise the result is always zero)
• The current version of the command editor explicitly allows using "This Event" (while also blending out other common special event IDs like Player, Boat, etc.. which wouldn't work. So this was a deliberate choice here.):

[Ghabry]

The "This Event" option makes indeed no sense. Looking at "Erase Event" it actually maps ID 0 to "This Event". So should be implemented the same way for consistency.

(btw I'll start reviewing your PRs next week, I take a "post release break" ;))