(svn r1407) -Codechange: changed a lot around _stations, _vehicles, _towns and _industries

(in prepare of dynamic arrays):
  - DEREF_XXX is changed into GetXXX
  - All direct call are directed via GetXXX
  - struct Industry has now an index-field
  - ENUM'd some stuff
  - Replaced home built loops with FOR_ALL_XXX
  - Added _stations_size, _vehicles_size, ... which gives the length of the
    array (which will be dynamic in the near future)
  - Changed lengtof(XXX) to _XXX_size (e.g. _stations_size)
  - Removed all endof(XXX) (because mostly it was part of a FOR_ALL_XXX)
  - Made the sort-functions of all 4 dynamic
  - Made all 4 Initialize functions more of the same
  - Some minor tab-fixing and stuff
  (tnx to Tron for proof-reading my 100kb patch ;))

  Note for all: please do NOT directly call _stations, _vehicles, _towns and
  _industries, but use the right wrapper to access them. Thank you.
  Ps: please also do not use 'v++', where v is of type Vehicle *.

ttd.c

@@ -482,6 +482,35 @@ void ParseResolution(int res[2], char *s)
 	res[1] = strtoul(t + 1, NULL, 0);
 }
 
+static void InitializeDynamicVariables(void)
+{
+	/* Dynamic stuff needs to be initialized somewhere... */
+	_stations_size = lengthof(_stations);
+	_station_sort = NULL;
+
+	_vehicles_size = lengthof(_vehicles);
+	_vehicle_sort = NULL;
+
+	_towns_size = lengthof(_towns);
+	_town_sort = NULL;
+
+	_industries_size = lengthof(_industries);
+	_industry_sort = NULL;
+}
+
+static void UnInitializeDynamicVariables(void)
+{
+	/* Dynamic stuff needs to be free'd somewhere... */
+	free(_station_sort);
+
+	free(_vehicle_sort);
+
+	free(_town_sort);
+
+	free(_industry_sort);
+}
+
+
 void LoadIntroGame()
 {
 	char filename[256];
@@ -640,6 +669,9 @@ int ttd_main(int argc, char* argv[])
 	// initialize airport state machines
 	InitializeAirports();
 
+	/* initialize all variables that are allocated dynamically */
+	InitializeDynamicVariables();
+
 	// Sample catalogue
 	DEBUG(misc, 1) ("Loading sound effects...");
 	_os_version = GetOSVersion();
@@ -721,6 +753,9 @@ int ttd_main(int argc, char* argv[])
 	// uninitialize airport state machines
 	UnInitializeAirports();
 
+	/* uninitialize variables that are allocated dynamic */
+	UnInitializeDynamicVariables();
+
 	return 0;
 }