Squashed 'External/Lagrangian/' changes from 80c89ad..1bb3228

1bb3228 Fix running tests in apps.
bdd9e9c Merge commit 'ffbc42886dc2f51749699d820c33f88c083fa4aa' into 2d-graph-contexts
d0e8ad1 Merge RXCollections in and update tests for Lagrangian.
e009966 Validate the project settings.
222af4c Node controllers can describe connection anchors by location.
993a5d9 Merge commit '4555c3b0fe23e97b91f022a7d0ae1e1c98da7a7e' into feature/variadic-nodes
2646ba5 Merge commit 'c79612e1a7f1c706fd7fb5239a1c3adad41c7534' into feature/variadic-nodes
fcbe0a3 Merge commit 'b056fcf4737d899afc6eb1f0eb2fa6823d2fdb65' into feature/goodbye-ocunit
6faa09e RXCollections/Lagrangian cleanliness. Merge commit '47f0e46aeed7e4fe2214d707433f936d82e18d62' into develop
79298d9 Merge commit 'be1e0c329461ff004ababf431cd7542de105d255' into develop
f71afde Merge commit 'ba646bc676f4d4fcefd92ff579b9c37c198aff4b' into develop
3501143 Merge commit '4b77cf27a654cae5816871f30fde7f7a1c9fa78f' into develop
29176d3 Merge commit '717c084bdc1a8fbeb1025a5655a760da84259d64' as 'External/RXCollections'

git-subtree-dir: External/Lagrangian
git-subtree-split: 1bb3228f9a5870b8490a59f8d1336602f3c9427a
Merge commit '5930e4ad207b2dde301a01220460a02c5ec59c19'