Generate cleaner config.xml that can be passed to setConfigXML

If the config.xml passed to setConfigXML has line breaks, it won't work.
So now we generate a cleaner XML without line breaks or indentation in the
class BigBlueButtonConfigXml.

refs #1129
Fix API calls that pass params with keys both as strings and symbols

Parameters can be passed with keys as symbols or strings, but sorting these
keys was generating errors if the types were mixed.
Fixes the error 'comparison of Array with Array failed'.

refs #1129