Changes in the Vendor System: 

m_vendor.c: completely rewritten.
	COMPAT BUSTER: 
	    #define SELL_OLD_OBJECTS: 
		If you define this vendors may not share a store-room.
	    The flag of query_items() is used to display long()'s now.
	#define MIN_VALUE 1: items cost at least 1 <currency>.
	Prices are now very low instead of very high. This is caused by the 
	  high exchange rates: set_value(100000) means 100 dollar or 1 gold.
	  so all set_value()'s should be multiplied with 1000.
	set_for_sale() and set_will_buy() now call functions with the object
	  to buy/sell as argument. Returned strings will be used as error msg.
	  Array of strings to determine allowed ids is still supported.
	Todo: compatibility of buying and selling vehicles

buy.c:	completely rewritten
	changed from command to verb
	allowing items consisting of multiple words
	added possibility to chose vendor with "from"

list.c:	completely rewritten
	changed from command to verb
	added possibility to chose vendor with "from"

ask.c:	uses flag = 1 for query_items(), so that long() gets printed.
	allows to ask about STR instead of WRD   
	(it is perhaps best to remove WRD rule)

sell.c	added possibility to leave out "to LIV" (e.g. new rule: "OBJ")
	needs the following addition to /std/object/vsupport.c:

	//:FUNCTION direct_sell_obj
	//Handle parser checks for "sell OBJ"
	mixed direct_sell_obj(object ob) {
	    return need_to_have();
	}