Updated Week 1 'recfun' assignment to progfun-004 session
Updated Week 2 'funsets' assignment to progfun-004 session
Updated Week 3 'objsets' assignment to progfun-004 session
Updated Week 4 'patmat' assignment to progfun-004 session
Updated Week 0 'example' assignment to progfun-004 session
Added Week 1: Functions & Evaluations assignment solution
Added Week 2: Higher Order Functions assignment solution
Added Week 3: Data and Abstraction assignment solution
Updated .gitignore with IDEA dirs
Added Week 4: Types and Pattern Matching assignment solution