parser.py: Adding default implementation of program grammar
parser.py: Adding default implementation of declarations grammar
parser.py: Adding default implementation of begin statement grammar
parser.py: Adding default implementation of statement grammar
scanner.py: Adding case for tokenizing comma
examples/assignment.pas: Updating assignment example
Removing extra spaces and print statements
parser.py: Implementing variable declaration grammar
parser.py: Fixing bug with infinite loop and returning control to main program
parser.py: Implemented symbol table for integers