use PyCallable_Check; export TK_VERSION and TCL_VERSION strings; some Tk 4.0 specific changes
use PyCallable_Check; export TK_VERSION and TCL_VERSION strings;
some Tk 4.0 specific changes

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator