Added TelephonyErrorEvent, removed attribute DOMError error (closes #56)
Events now extend Event, instead of EventTarget (closes #60)
renamed conference attr, moved it to TeleponyCall (closes #55)
Small rewrite of attribute call
fixed up text of attributes for two events
Removed text that needs to be handled by an algorithm
Removed incorrect use of InvalidModificationError (closes #61)
Removed commented out event handlers stuff not used in the spec
Made the document valid HTML5 (closes #62)
Added changeDefaultService() and steps (closes #54)

First draft.
fixed whitespace
Fixed a small comment
Added Telephony task source (closes #18)
Merge pull request #64 from marcoscaceres/error_handling

Lots of fixes, please see the commit list for changes and bugs closed