Add support for binary numbers

Add support for binary (:bin, 0b1101, etc.) numbers.

Add autoload support

Move most of the functionality to autoload directory.

Bugfix Release

Fix bugs which led to errors when using VimCalc3 with other plugins.

v3.1

Allow real numbers without leading 0 and with capital E.

Port to Python 3

v3.0

Port to Python 3 (+python3)