fix for tree interpolation
merged with unstable
working on python interp
merging with unstable
merged python interp changes
removing python changes for interp
added simple interpolation bindings for python
doc fix for interpolation bindings for python
partial fix to model generation bug for non-linear constraints: avoid epsilon refinment for non-shared variables

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
Merge branch 'unstable' of https://git01.codeplex.com/z3 into predabst
avoid osx build error
todos related to use of optional

Signed-off-by: Andrey Rybalchenko <rybal@microsoft.com>