fixed #103 (the height, not categories)
various fixes and improvements to spellbook and spells
fixed #106
hovering over a target without a challenge rating will not give an error anymore
reach talent now makes a regular attack, improvement to shoot and reach code, and added possibility for special prequisites for talents to be preused
Merge pull request #108 from Sebsebeleb/master

improvements to spellbook and some general fixes