History for SafeBlock

??changed:
-
SafeBlock is defined in 'zbytecodehacks/VSExec.py'.

SafeBlock is a subclass of CodeBlock.  It forbids all 'EXEC_*' opcodes,
'DELETE_*' opcodes, and 'STORE_*' opcodes
except 'STORE_FAST', 'STORE_GLOBAL', and 'STORE_SUBSCR'.  This prevents
the use of the 'exec' statement, 'del' statement, and any assignment
statement except bare local, global, or item assignment.  Item assignment
is allowed so that literal dictionaries can be created, and is further
restricted by the AllowMapBuild Munger.

It includes the Printing, PublicNames, and AllowMapBuild Mungers.  These
redirect the 'print' statement, prevent use of variable and attribute
names beginning with underscore, and allow literal dictionaries while
preventing item assignment.