Merge pull request #74 from uzername/master

Some new information to developer's FAQ. That's my pull request.

DEVELOPER_FAQ.txt

@@ -36,6 +36,28 @@
  7) Just like attacks, some monsters may have a special function called when
     they die.  This works the same as attacks, but the relevent files are
     mondeath.h and mondeath.cpp.
+1.3 Adding structures to the map
+  Most "regular" buildings are spawned in cities (large clusters of buildings which are located rather close to each other). 
+  In file omdata.h in the enum oter_id structure define names (code identifiers) for your building. 
+  If you want your building to be displayed at overmap in different orientations, you should add 4 identifiers for each orientation (south, east, west and north correspondingly). 
+  In the same file in structure const oter_t oterlist[num_ter_types] 
+  we should define how these buildings will be displayed, how much they obscure vision and which extras set they have. For example:
+      {"mil. surplus",  '^',	c_white,	5, build_extras, false, false},
+      {"mil. surplus",  '>',	c_white,	5, build_extras, false, false},
+      {"mil. surplus",  'v',	c_white,	5, build_extras, false, false},
+      {"mil. surplus",  '<',	c_white,	5, build_extras, false, false}
+  Comments at the beginning of this structure are rather useful.
+  In the file mapgen.cpp find the subroutine called draw_map(...); 
+    there you should find a huge variant operator ("switch") 
+    where you should put your code defining the new building by adding new case-statement.
+  This should be mentioned that most buildings are built on the square SEEX*2 x SEEY*2 tiles.
+  If you want your building to be spawned not only in city limits 
+     you should refer to structures in file omdata.h 
+     (starting from the line #define OMSPEC_FREQ 7). 
+     These structures are commented in source code. Add new identifier in enum omspec_id structure before 
+     NUM_OMSPECS and then add a record in const overmap_special overmap_specials[NUM_OMSPECS] array. For example:
+         {ot_toxic_dump,	   0,  5, 15, -1, mcat_null, 0, 0, 0, 0, &omspec_place::wilderness,0}
+  The comments given in source code to structure struct overmap_special explains the meaning of these constants in the example above. 
 
 
 	FAQ