Fenics-ffcx

---------------------

- Improve formatting of floats with up to one non-zero decimal place.
- Fix bug involving zeros in products and sums. Bug 804160.
- Fix bug for new conditions '&&', '||' and '!' in UFL. Bug 802560.
- Fix bug involving VectorElement with dim=1. Bug 798578.
- Fix bug with mixed element of symmetric tensor elements. Bug 745646.
- Fix bug when using geometric coordinates with one quadrature point

-------------------

- Change license from GPL v3 or later to LGPL v3 or later
- Add some schemes for low-order simplices
- Request quadrature schemes by polynomial degree (not longer by number
of points in each direction)
- Get quadrature schemes via ffc.quadrature_schemes
- Improved lock handling in JIT compiler
- Include common_cell in form signature
- Add possibility to set swig binary and swig path

------------------

- Add support for generating error control forms with option -e
- Updates for UFC 2.0
- Set minimal degree to 1 in automatic degree selection for expressions
- Add command-line option -f no_ferari
- Add support for plotting of elements
- Add utility function compute_tensor_representation

------------------

- Added memory cache in jit(), for preprocessed forms
- Added support for Conditional and added demo/Conditional.ufl.
- Added support for new geometric quantity Circumradius in UFL.
- Added support for new geometric quantity CellVolume in UFL.

------------------

- Make global_dimension for Real return an int instead of double, bug 592088
- Add support for facet normal in 1D.
- Expose -feliminate_zeros for quadrature optimisations to give user more
control
- Remove return of form in compile_form
- Remove object_names argument to compile_element
- Rename ElementUnion -> EnrichedElement
- Add support for tan() and inverse trigonometric functions
- Added support for ElementUnion (i.e. span of combinations of elements)
- Added support for Bubble elements
- Added support for UFL.SpatialCoordinate.

------------------

- Bug fix in removal of unused variables in Piola-mapped terms for tensor
representation