removed headers from common.h

causing errors by including header files before the structures
referenced within are defined
created structures header file for easy inclusion
whoops
added structures.h to Token.h
Corrected sprintf to print line as an integer
corrected sprintf to printf
removed structures.h

unnecessary, token.h only needs to include LineList.h
added IdentifierTree to Print.h
minor corrections

changed tree in main to tree*, changed sprintf in printTree to printf.
fixed reference to function
fixed line number insertion
added identifierTree tree to header
fixes to LineNode
added stdlib for atoi
corrected function call for printTree
corrected references to tree
removed unneeded code
removed more unneeded code
removed second declaration for tree
changed name of tree