Convert to Swift 3

[akirmse]

There are some errors when compiling under Swift 3:

/Users/akirmse/peakbagger/ios/Peakbagger/Peakbagger/GlimpseXML/GlimpseXML/GlimpseXML.swift:83:76: 'init' is unavailable: use 'withMemoryRebound(to:capacity:)' to temporarily view memory as another layout-compatible type.
/Users/akirmse/peakbagger/ios/Peakbagger/Peakbagger/GlimpseXML/GlimpseXML/GlimpseXML.swift:212:109: 'nulTerminatedUTF8' is unavailable: Please use String.utf8CString instead.
/Users/akirmse/peakbagger/ios/Peakbagger/Peakbagger/GlimpseXML/GlimpseXML/GlimpseXML.swift:455:76: 'init' is unavailable: use 'withMemoryRebound(to:capacity:)' to temporarily view memory as another layout-compatible type.
/Users/akirmse/peakbagger/ios/Peakbagger/Peakbagger/GlimpseXML/GlimpseXML/GlimpseXML.swift:760:41: 'init(allocatingCapacity:)' is unavailable: use 'UnsafeMutablePointer.allocate(capacity:)'
/Users/akirmse/peakbagger/ios/Peakbagger/Peakbagger/GlimpseXML/GlimpseXML/GlimpseXML.swift:762:25: 'fromCStringRepairingIllFormedUTF8' is unavailable: Please use String.init(cString:) instead. Note that it no longer accepts NULL as a valid input. See also String.decodeCString if you need more control.