Knapping Skill and Quality of Life Improvements

In this version, I did the following things:

• Added a message when I can no longer craft the thing I've been crafting.

• Added an autosave slot

• Fixed some stuff about the save and load screens

• Added context sensitive help for skills

• Added an achievement for the number of times  you have crafted something

• Added a knapping skill

• Added skill level requirements for crafting things

• Added a maximum skill level for skills