Fix fema and evac center

Somehow the ruble fix ff333b852c3bf549d1bb953e3a0b7ec313934811 damaged the evac center definition:

The mapping "1" to `t_window_boarded` got lost. But the mapgen json contained the "fill_ter" setting, so mapgen ignored that un-mapped "1" and put the "fill_ter" (`t_floor`) there. Result is: no boarded up windows, but floors instead.

I re-added the mapping, and also the missing mappging from "0" to `t_door_locked_interior` (which has also been lost).

To check that everything is well-defined I removed the "fill_ter" setting and added (where needed) the mapping " " to `t_floor`. This was covered by the "fill_ter" setting before - the game again ignored the un-mapped character " " and put the default terrain `t_floor` there - now it's an explicit mapping and any missing mappings will be reported again.

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The FEMA camp has corpse filled pits, those are surrounded by `t_dirtfloor`. But `t_dirtfloor` has the indoors flag. The other parts of the the FEMA camp correctly use `t_dirt`, fixed this, too.

Apparently this has always been that way, but it gives weird light issues (under the right weather) and because `t_dirtfloor` has the INSIDE flag, it also prevents from weather effects:

![screenschot-2014-09-30-21-59-26](https://cloud.githubusercontent.com/assets/5095435/4468287/6fad14a4-48fb-11e4-8be8-6a02a3ca5c29.png)

The gray part is the `t_dirtfloor`, the character is still outside, the dirt floor is inside and has less light.