Vcs: Jump to the current source line in Fossil Annotate editor

* Keep track of the current source line number and pass it to Annotate
  action.
* Add a 'List Versions' toggle in Annotate editor to prepend a list of
  commits that make up the annotated source.
* By default do not show the version list so that annotated line number
  could be matched to the source line.

NOTE: VcsBaseEditorWidget::configurationWidget() query is no longer
available, yet Fossil client needs it in order to process the effective
arguments. So we re-implement it in FossilEditorWidget sub-class.

Change-Id: Idc4c21d074ccf4e1c6d041cce2abceb78665c8f2
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

plugins/fossil/fossilsettings.h

@@ -38,6 +38,7 @@ public:
     static const QString diffIgnoreAllWhiteSpaceKey;
     static const QString diffStripTrailingCRKey;
     static const QString annotateShowCommittersKey;
+    static const QString annotateListVersionsKey;
     static const QString timelineWidthKey;
     static const QString timelineLineageFilterKey;
     static const QString timelineVerboseKey;