fixes printing problems for string errors, now checkProgram gets the LErrors from the Lexer runAlex', and at the end reports everything.
better error reporting for string errors, now using Seq instead of [a] in the lexerErrors list, making the errors in this program insted of tuples, fixed some styling
started trying the errorTk, it doesn't seem to work. Now we simulate the string was correctly constructed when it's missing a ". parseProgram not returning Either anymore, now returns what it parsed, and all the errors in a tuple.
SymbolTable: ability to peek in the Stack. Sapphire: adapting to changes in Lexer and Paser and the way the take/return values