(svn r6709) -Fix r6679: [build train window] solved an issue that could lead to trailing empty blocks in the list array
Since they were freed with the rest of the array, it only meant that we wasted a few bytes (max 16) while the window were open and we didn't leak memory

/* $Id$ */

KNOWN BUGS / PROBLEMS:

Normal and elrail depots look the same. Use 'X' (transparent buildings)
   to distinguish between them
Missing curors / icons for construction (currently using the conventional ones)