(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 *.

industry.h

@@ -23,12 +23,25 @@ struct Industry {
 	byte color_map;
 	byte last_prod_year;
 	byte was_cargo_delivered;
+
+	uint16 index;
 };
 
 VARDEF int _total_industries; // For the AI: the amount of industries active
+
 VARDEF Industry _industries[90];
-#define DEREF_INDUSTRY(i) (&_industries[i])
-#define FOR_ALL_INDUSTRIES(i) for(i = _industries; i != endof(_industries); i++)
+VARDEF uint _industries_size;
+
+VARDEF uint16 *_industry_sort;
+
+static inline Industry *GetIndustry(uint index)
+{
+	assert(index < _industries_size);
+	return &_industries[index];
+}
+
+#define FOR_ALL_INDUSTRIES(i) for(i = _industries; i != &_industries[_industries_size]; i++)
+
 VARDEF bool _industry_sort_dirty;
 void DeleteIndustry(Industry *is);