Camera tracking integration

===========================

- Fixed some silly things ni DNA design. Now all
  reconstruction data is stored in Tracking->Reconstruction.
  Please, re-solve your cameras -- reconstruction data
  wouldn't be read from files saved in blender below this
  commit.
- RNA accessors for reconstruction data.
- Store average reconstruction error in new reconstruction
  structure and show it in clip editor header after
  reconstruction.
- Highlight failed to reconstruct frames with red in cache line.
- Added "group" "Failed Tracks" in Select Grouped operator,
  Meant to be used for selecting tracks bundles from which
  failed to to be solved.
- Hotkey to delete marker: Shift-X.
- Jump to next/prev failed frame operator. Hotkeys are
  Ctrl-Shift-Left/Right Arrow.

release/scripts/startup/bl_ui/space_clip.py

@@ -113,6 +113,12 @@ class CLIP_HT_header(bpy.types.Header):
         layout.template_ID(sc, "clip")
         layout.template_running_jobs()
 
+        if clip:
+            r = clip.tracking.reconstruction
+
+            if r.is_reconstructed:
+                layout.label(text="Average solve error: %.4f"  % (r.average_error))
+
 
 class CLIP_PT_tools(bpy.types.Panel):
     bl_space_type = 'CLIP_EDITOR'
@@ -577,6 +583,9 @@ class CLIP_MT_select_grouped(bpy.types.Menu):
         op = layout.operator("clip.select_grouped", text="Select Disabled")
         op.group = 'DISABLED'
 
+        op = layout.operator("clip.select_grouped", text="Select Failed")
+        op.group = 'FAILED'
+
         op = layout.operator("clip.select_grouped", text="Select by Color")
         op.group = 'COLOR'