Fix float parsing bug that manifests on Qt4.6 and later.

This file relies on Qt's QDataStream to handle the parsing
of primitive C types from Computrainer .3dp files, including
floats.  In Qt4.5 and earlier, Qt defaulted to 32 bit
floats.  In Qt4.6 and later, Qt started using 64 bit
floats by default.  As a side-effect, parsing broke on
Qt4.6, leading to a crash when importing or using .3dp files.

This patch fixes the issue by using QDataStream's
"setVersion()" method to tell Qt to use the Qt4.0 serialization
format for the QDataStream used in this file.  This
patch does not affect any other files.  This patch
should make the formatting assumptions both backwards
and forwards compatible.

src/Computrainer3dpFile.cpp

@@ -60,6 +60,12 @@ RideFile *Computrainer3dpFileReader::openRideFile(QFile & file,
     }
     RideFile *rideFile = new RideFile();
     QDataStream is(&file);
+
+    // Note that QT4.6 and above default to 64 bit floats.  For
+    // backwards and forwards compatibility, we'll freeze the stream
+    // version we use for parsing at 4.0, and then add in LittleEndian
+    // number format, which is what Computrainer3dp has.
+    is.setVersion(QDataStream::Qt_4_0);
     is.setByteOrder(QDataStream::LittleEndian);
 
     // start parsing the header