Move DialogType enum back into header

Fixes build of OS X-specific code in Dialog.mm, which was broken in
commit a3b336.

See: bug #620
When a bow is equipped, hero screen shows the base damage from arrows.
The lower limit of player's Attributes and Stats is 1 now.
Set the default duration of "Confuse" spell to 5 seconds.
^GAMEDAYS variable now gets the amount of days, rather than their tens.