- add JIN (chinese weight measure)

- Add popup dialog box when "write units" to explain that writing
  goes to standard output. to write to filename.txt gonvert must 
  be started in console mode as follows:
    gonvert > filename.txt
    
- add AWG (American Wire Gauge) conversions from Diameter/length and Area.

- add volume of a sphere with diameter given in:
	- inches, feet, metres, cm.
	
- add subcategories, especially for common measures:
	- length,area,mass: all,foriegn,ancient
	
- add saveable customisable units for derived unit categories:
	- accelation (length/time²)
	- angular velocity (angle/time)
	- Computer data flow rate (computer data/time)
	- density (mass/volume)
	- energy | work ( force · time)
	- flow dry/liquid (volume/time)
	- velocity (length/time)
	- fuel efficiency: (length/volume) (NEW*)
	- etc...
	- probably use pickle method
	- probably use pop up window to define numerator and denominator units
	  each with pull down selections.
	
- detailed instructions for creating your own conversions
- Morse code converter
- add:	- angular acceleration
	- torque
- add ASCII to computer numbers (convert Hex to ASCII)

- Add bookmarks (certain categories and units preselected, Ex:
	^A add bookmark
	^B view bookmarks
	edit bookmarks
	^right ^left to go to previous and next bookmarks
	command line option to start up with bookmark

- Add history (possibly similar to bookmarks)
	- a popup dialog showing last x pairs
	- ability to remove a pair from history
	- display group:unit1[,unit2]