Pythonic layer prevents access to `load` and `loadfile`

[jgray-19]

In the current form, PyMAD-NG does not allow access to the functions load and loadfile in MAD-NG, as there already exist functions called these in the python object.

To improve do one of the following:

• Rename these functions
• Extend the functionality to do identical behaviour as MAD-NG, plus the additional behaviour that it currently does.

For now, this is a minor issue and will only be fixed if requested. Otherwise, the workaround is to used load and loadfile in a string with mad.send("""...""")