Fixed EndlessGrid not rendered in Custom Node. Problem is EndlessGrid's VM not knowing when to start

EndlessGridView only loaded should inform its EndlessGridViewModel about it,
then ViewModel is able trigger the first render.
Merge pull request #726 from l2obin/EndlessGridFix

Fixed EndlessGrid not rendered in Custom Node causing canvas control issues
search term updates
Obtain all elements of type using DocumentManager, Unit tests for ElementFactory
Merge pull request #729 from ke-yu/ChocoButter

Implement AstBuilder.CompileToAstNodes()
Renamed ElementFactory to ElementSelector, Implemented CurveLoop with unit tests
More tests for CurveLoop
Unit tests for DSSolid.ByExtrusion
Added GraphicsManager class for setting the tesselation level of detail, added tesselation method for DSSolid
Unit tests for DividedPath
Big cleanup wrt AstBuilder and ProtoAst gen
Implemented IGeometryObject to enforce tesselation of implementers
removed unnecessary code
Get Edges from Solid, implemented DSEdge, updated csproj
Merge branch 'ChocoButter' of https://github.com/ikeough/Dynamo into ChocoButter
MAGN-551. Changed line and point colors to not multiply. Removed line stripping logic.
Merge branch 'master' of github.com:ikeough/Dynamo
MAGN-655. Remove tick snapping from number slider.
Merge branch 'master' into ChocoButter
Updte AstBuilder.CompileToAstNodes() to support delta execution