0.9.13

Description

• Better handling of empty strings passed as input.
• Fix the shift safe number issue from 0.9.12
• More minor pylint / etc fixes / cleanups (general code quality)
• separate .parse from #115
• Allow setting up completely empty {} operators / functions ( #75 via #123 )
• Add extra bit-ops from #87
• Add @daxamin to contributors ?
• Version bump stuff.
• other readme tweaks
• star expressions, eg x = {"a": 1, "b": 2, **c}