(svn r2290) - CodeChange: protect the next batch of commands. This brings us to a total of 61, which is 53% :)

- CodeChange: To correctly accept engine-prototypes, the best-player checking has been moved to its own function, I hope it functions the same as before.
- CodeChange: Added symbolic types of PlayerID, OrderID and EngineID. For engines also added GetEngine() and IsEngineIndex(), similar to the other such functions.
- CodeChange: To correctly build industries, some tables have been moved to build_industry.h. The only way to find out currently if an industry is valid in a climate is by looping all industries and checking if it matches. Also to comply with the patch setting build_rawmaterial_industries, it is assumed that these industries do not accept any cargo of any type. This can and probably should changed in the future to some flag in their struct. Also use _opt_ptr instead of _opt.
- CodeChange: implemented the HQ checking code inspired by MarkR2 in "[ 1190944 ] Many commands not checked for security".  Unfortunately it is impossible to prevent only deleting a HQ by a modified client atm.
- CodeChange: For insert order and modify order their parameters are implicitely truncated to 8 bits, instead of the 16 bits said in the comments.

table/build_industry.h

@@ -1111,6 +1111,13 @@ const	byte _industry_type_costs[37] = {
 	187, 193,  17,  20, 192,  22, 203, 213, 210
 };
 
+const byte _build_industry_types[4][12] = {
+	{ 1,  2, 4,  6, 8, 0, 3, 5,  9, 11, 18 },
+	{ 1, 14, 4, 13, 7, 0, 3, 9, 11, 15 },
+	{ 25, 13, 4, 23, 22, 11, 17, 10, 24, 19, 20, 21 },
+	{ 27, 30, 31, 33, 26, 28, 29, 32, 34, 35, 36 },
+};
+
 
 static const byte _industry_create_table_0[] = {
 	4, 4,