Added "equal proportional" and "equal nonempty" for symmetry.
select:equal now takes weights into account.

parse_enum function throws if the string can not be parsed

Changed default settings for Magic to more closely match real Magic sets.
Minor adjustments to magic-new-split.

magic pack template now uses 'pack type' instead of 'pack item'

don't allow a new pack to be 'removed'

custom pack types can now be removed again.

use set_help_text instead of the previous thing in SetWindow.

   typing1 Ctrl+Z Ctrl+Y typing2 Ctrl+Z
removes just typing2, not both.

There is no UI for using these custom types yet.

- added DoGetBestSize to PackTotalsPanel, so the text always fits