Add test cases to test suite 'positive':
- op_ex_mod_int:
	Example of integer a modulo
- overload_operator1:
	operator overloading with override

Add test cases to test suite 'negative':
- bin_op_ambiguous_error1:
	Ambiguous binary operator
- bin_op_ambiguous_error2:
	Check the return type of binary operator at TypeCheck
- bin_op_not_found_error1:
	Binary operator not found
- print_not_found_error1
	Print function not found
- unary_op_not_found_error1
	Unary operator not found

Modify test cases:
- miscerror:
	Modify the error message of BadPrintArgError

Add support for operator overloading:
- Binary operator:
	+ : add
	- : sub
	* : mul
	/ : div
	% : mod
	&&: and
	||: or
	==: eq
	!=: ne
	< : lt
	> : gt
	<=: le
	>=: ge
- Unary operator:
	- : neg
	! : not
- print function

Binary operator overloading:
- Try to find op and rop, if ambiguous then issue an error

Modify AST:
- Add member callExpr to some of the nodes to store operator function

Add errors:
- BinaryOperatorAmbiguousError:
	Ambiguous candidates for binary operator
- BinaryOperatorNotFoundError
	No method match the binary operator
- UnaryOperatorNotFoundError
	No method match the unary operator

Add test cases:
- visit_ident_error1:
	visit a function table identifier

Add type FuncTableType and return it in FunctionTable.getType
Solve the null pointer return value at TypeCheck.visitIdent

Add test suite original_error for compilation error tests

Add test cases:
- inher_overload1:
	Overload combining with inheritance

Fix the output of ClassScope to iterate over all Functions
	in all FunctionTables

Add test cases:
- overload_multi2:
	Tests of overloaded functions with multiple parameters

Add test cases:
- overload_error2:
	Overload errors

Check only methods which can be a valid call
	while checking whether a function can be a candidate

Add runAll.py to run all specified test suites

Fix runAll.py to remove test case blackjack if exists

Add test cases:
- overload_error1:
	Overload errors
- override_error1:
	Override overloaded functions errors
- redef_error1:
	Redefinition errors

Add test cases:
- overload_single1:
	Tests of overloads functions with single parameters
- overload_multi1:
	Tests of overloaded functions with multiple parameters

Add runAll.py to run the test suite

Add runAll.py to run the test suite

Modify symbol.Class.resolveFieldOrder:
- handle overloaded functions while calculating the offset
	of each member of a class

Modfiy translate.Translater.fillVTableEntries:
- handle overloaded functions while building VTable

Modify translate.Translater.createFuncty:
- replace the function names with function signatures

Add FuncUtils:
- getCallFunction:
	Get a suitable function symbol for a specific call
		or return an error
	Return value is of type getCallFunctionReturn
- getArgListString:
	Get the string of a function with function name and parameter list

Modify the process of building the symbol table:
- visitMethodDef:
	Modify the function table with this name
		instead of inserting a single function
	Add the signature of this function into the table
- checkOverride:
	Check overrides of overloaded functions
- isMainClass:
	Issue errors if main function is overloaded

Modify type checks:
- call FuncUtils.getCallFunction to get the symbol
	of this function call

Modify symbol Function:
- toSignature:
	Return the signature of this function
- conflictArgList:
	Check whether this function is conflicted with another

Add errors:
- AmbiguousNewDeclarationError:
	Ambiguous new declarations
		with the same parameter list but different return values
- ConflictMainError:
	Multiple main functions
- MethodCallAmbiguousError:
	Ambiguous method matches the method call
- NoMatchMethodError:
	No method matches the call
- RedefinitionError:
	Redefine the same function
- VarOverrideMethodError:
	Try to override the method with a variable

Add CommonUtils:
- copyList: shallow copy a List

- Add symbol FunctionTable to store the overload table of a function
- Add function isFunctionTable in Symbol to check the type