FIX: Asterisk authentication now supported.
NEW: Dial priority settable in SIP provider settings. A priority of 1 means the set of lines will be used (if available) for dialing from the directory or when pressing the dial button (e.g. any time a specific line is not selected by clicking it). Solo will then search any lines with a priority of 2 etc until it finds an available line. A priority of 0 means the lines will not be tried.
NEW: Strip number and prefix number settings added to SIP provider. Allows numbers to be automatically prefixed or stripped from phone numbers (e.g. to add a 9 before all numbers, or remove a preceeding 0 on all numbers with more than 5 digits).
