Small changes to check_syntax.
Merge branch 'designProject' of https://github.com/nfischer/CS111Lab1 into designProject

Conflicts:
	read-command.c
Merge branch 'designProject' of https://github.com/nfischer/CS111Lab1 into designProject
check_syntax_errors_2 now handles case, for, while, until, if, and subcommands. Different implementation than check_syntax_errors, uses single stack.