Convert an XML
document into a nested python dict.
from_xml(data)
Parameters:
data - a string or file object containing XML data
Return:
dict version of the data parameter
>>> from ergaleia import from_xml
>>> from_xml('<A>1</A>')
{'A': '1'}
>>> from_xml('<parent><child>fred</child><child>sally</child></parent>')
{'parent': {'child': ['fred', 'sally']}}