Adding zone input validation, better use of enums, refactoring, and better testing

Author: lamkina

Diff for: baseclasses/utils/__init__.py

@@ -2,7 +2,7 @@
 from .error import Error
 from .fileIO import readJSON, readPickle, redirectingIO, redirectIO, writeJSON, writePickle
 from .solverHistory import SolverHistory
-from .tecplotIO import TecplotZone, TecplotFEZone, TecplotOrderedZone, readTecplot, writeTecplot
+from .tecplotIO import TecplotFEZone, TecplotOrderedZone, TecplotZone, ZoneType, readTecplot, writeTecplot
 from .utils import ParseStringFormat, getPy3SafeString, pp
 
 __all__ = [