Merge pull request #55 from blackwarthog/master

add missed file
Change grid color through metadata
Use the right iterators to access the color channels at the metadata panel
Merge pull request #58 from synfig/grid_color

Grid color
Add new constructor to Vector class based on radius and angle.
When adding ducks in duckamtic, do not use the component index directly.
Get the index by name.
When calculating the reverse of a BlinePoint, use its internal reverse
member instead of figure out externally.
Refactor class BLinePoint:
1) Replace split_tangent by the combination of split_tangent_ragdius and
split_tangent_angle.
2) Add new private members to retrive the combination of both flags for
full split or full merged
3) Add two new private members to store the tangent2 to return for the
possible split flags combinations (tangent2_radius_split and tangent2_angle_split)
4) New private member function update_flags to update new flags from 2)
5) New private member to update the tangent2 accordingly to the flags.
6) Update callbacks to BLinePoint members where applicable.
Incorporate the new members to ValueNode Composite.
Fix loadcanvas to allow properly load old files.
When angles are linked, avoid update angle of tangent2 if radius of tangent1 is zero
Clarify logic when getting tangent2
When adding tangent 2 handle, use its own value description, regardless the splits flags
When handling tangent 1 or tangent 2 with the handle, update the other tangent based on the split flags.
When merging or splitting the radius or the angle, update the other tangent.
Fix BLinePointTangentMerge and BLinePointTangentSplit to properly use the new members of BLinePoint
Add actions to split/merge angle/radius of tangents individually.
Use the new members of BLinePoint correctly in the layers.
Do not assume that parent of BLinePoint is always a LinkableValue Node
Allow widget curves to draw all the components of the BlinePoint
Restore the SHIFT click/drag functionality over a tangent handle for full split it.