Ride editor and tools

A new tab 'Editor' for manually editing ride file data points and
associated menu options under 'Tools' for fixing spikes, gaps, GPS
errors and adjusting torque values. A revert to saved ride option
is also included to 'undo' all changes.

The ride editor supports undo/redo as well as cut and paste and
"paste special" (to append points or swap columns/overwrite
selected data series). The editor also supports search and will
automatically highlight anomalous data.

When a file is saved, the changes are recorded in a new metadata
special field called "Change History" which can be added as a
Textbox in the metadata config.

The data processors can be run manually or automatically when a
ride is opened - these are configured on the ride data tab in
the config pane.

Significant changes have been introduced in the codebase, the most
significant of which are; a RideFileCommand class for modifying
ride data has been introduced (as a member of RideFile) and the
RideItem class is now a QObject as well as QTreeWidgetItem to
enable signalling. The Ride Editor uses a RideFileTableModel that
can be re-used in other parts of the code. LTMoutliers class has been
introduced in support of anomaly detection in the editor (which
highlights anomalies with a wiggly red line).

Fixes #103.

src/RideMetadata.cpp

@@ -221,7 +221,13 @@ FormField::FormField(FieldDefinition field, MainWindow *main) : definition(field
             widget = main->rideNotesWidget();
         } else {
             widget = new QTextEdit(this);
-            connect (widget, SIGNAL(textChanged()), this, SLOT(editFinished()));
+            if (field.name == "Change History") {
+                dynamic_cast<QTextEdit*>(widget)->setReadOnly(true);
+                // pick up when ride saved - since it gets updated then
+                connect (main, SIGNAL(rideClean()), this, SLOT(rideSelected()));
+            } else {
+                connect (widget, SIGNAL(textChanged()), this, SLOT(editFinished()));
+            }
         }
         break;