Added comment above checkStep() about the warning that it is unused.
The comment was that it is used in ProofChecker.html so I currently don't know why it is not noticing this.
Added an if statement to check that sel.hasOwnProperty(sect).
This fixed the warning for sect attribute.
Added if statement to for loop at line 33.
This fixed warning that for loop was iterating rule without knowing if it had a hasOwnProperty.
Fixed href="" in <link> for rel="stylesheet".
This fixed warning about unresolved href="".
Rewrote History() so that it uses an array to keep track of the data.
Not currently working yet.
Fixed warning about an unused local variable sub.