& btstores()
 
  Syntax: btstores(<MapDB>[,<partname>])
 
  This function returns a list of parts in the specified unit or 
  hangar.
 
  The format of the list is <partname>:<amount>|
 
  The function accepts an optional argument of a partname in which 
  case it returns the amount of that part located in the unit/hangar
 
	Note: This will work on units to see their cargo manifest, useful 
	for carriers and other things.
 
  Error Messages:
 
  * If <MapDB> is not valid the function will return #-1 INVALID 
    TARGET
  * If <partname> optional argument is included and is not a valid 
    partname the function will return #-1 INVALID PART NAME 
 
  Example:
  Given that #62 is a valid bay
 
  > think btstores(#62)
  Armor:5|Engine:5|IS.LargeLaser:2
  > think btstores(#62,Armor)
  5
