Replaced "NodeModel.OldValue" with "NodelModel.CachedValue"
Updated all relevant test cases to use "NodeModel.CachedValue"
MAGN-3023. Port Sun Path node.
Remove old updater, and add some notes.
Clear selection nodes references when document switching. Improve document switching messages.
Repopulate drop-down nodes when document switching.
Revert "Remove old updater, and add some notes."

This reverts commit 0c2bcd2e04fc77051b2fef8fffd851db81036703.
Revert "MAGN-3023. Port Sun Path node."

This reverts commit 3f54726c2bd9e2e6c4533908c9e3a90581a87436.
Merge branch 'master' of github.com:DynamoDS/Dynamo
Revert "Revert "MAGN-3023. Port Sun Path node.""

This reverts commit 2d5df6bc16c2ae374b1dfd93a1264756c5131e3b.
Revert "Revert "Remove old updater, and add some notes.""

This reverts commit f4f718f25a967825fe96ae1096ad39077dcd7d25.
Merge branch 'master' into PainKiller

Conflicts:
	src/DynamoCore/Models/NodeModel.cs
	src/DynamoRevit/VisualizationManager/VisualizationManagerRevit.cs
Migrate SunPath Direction
Refactor function initializer into the functiontable class
append the curveElement.curve node
Add type conversion to migration
Merge pull request #1579 from junmendoza/GlobalFuncTable_Initialize

Refactor function initializer into the functiontable class
Merge pull request #1580 from Zhengzi/Migration

append the curveElement.curve node
Merge pull request #1578 from ellensi/master

Migration
append element.geometry node to it