Add ENOTDIR constant
Fixes in bit string building
Better NotImplemented messages
Handle attempts to write to a non-writable file
Add erlang:binary_to_integer/2 BIF
Fix erlang:binary_part/3 guard BIF
Fix eta bag implementation
Add string:to_integer/1 and string:to_float/1 BIFs
Add erlang:binary_to_term/2

This adds a "safe" mode, which currently only
disallows new atoms.  Future addition could be
to only allow resolving existing Funs.
Update JCraft JZLib, fix driver ByteBuffer usage
Fix unicode char collection
Improve exception display
Fix erlang:delete_module/1 to return expected values