Introduction of context structure: It stores a reference to the AST entry of the current loop. Nested loop are handled in stack fashion. Handling of enter and exit can be done similar to scopes with respective enter and hide functions (related to #14)

add label entries to AST nodes (related to #14)

update example2.c

add d_type field to binary and unary expression AST nodes (related to #14)

change parameter of get_data_type to the symbol table entry directly. no need for lookup

Introduction of three address code source and header files. First implementation (related to #14)

introduce temporary compiler-generated symbol table entry type (related to #14)

Main steps of semantic analysis concluded. Next steps in #14. (closes #13)

fix line number assignment for function (related to #13)

verify function name not a redeclaration, fix line number assignments in AST, introduce symtab helper for retrieving first line (related to #13)

update debugging messages (related to #13)

extend simple C language documentation on semantics: add function calls, assignments, jump statements, print statements and return statements (related to #13)

verify binary and unary expression data type is not of type UNDEF or VOID (related to #13)

verify output value of expression in print statement is not of type UNDEF or VOID (related to #13)

update README.md