Sage-flatsurf

====================

**Changed:**

* SimilaritySurface.edge_matrix becomes a cached_method

**Removed:**

* Removed unused functions from matrix_2x2, namely, `number_field_to_AA`,
`homothety_rotation_decomposition`, `is_similarity`, `rotation_matrix_angle`.

====================

**Performance:**

* Improved acting with a matrix on a polygon by not checking convexity of the result.

====================

**Fixed:**

* Fix determining base ring in `from_pyflatsurf` when importing surfaces from pyflatsurf.
* Include orbit closure module in documentation at https://flatsurf.github.io/sage-flatsurf.

**Performance:**

* Improved performance of erasing marked points by Delaunay triangulating first.

====================

**Changed:**

* Got rid of the FlowDecomposition wrapper in gl2r_orbit_closure.py.

**Performance:**

* Improved performance of rank computations when computing orbit closures by
using a faster algorithm for residue fields, see
https://trac.sagemath.org/ticket/33273.

====================

**Added:**

* Added another example of an explicit orbit closure computation to the documentation.
* Added better error messages when an optional dependency is not installed,
pointing out how this dependency could be satisfied.

**Changed:**

* The `copy` parameter of `Surface_list.__init__()` and
`__Surface_dict.__init__()` now defaults to `surface.is_mutable()`. Before
the default was `True`. However, in principle this should not break any
existing code but only change the runtime slightly in some cases.

* The `mutable` parameter of `Surface_list.__init__()` and
`Surface_dict.__init__()` now defaults to `True`. Before its default was
`False` in many cases. This change might break some existing code. If it
does, one needs to either explicitly set `mutable=False` in this invocation or
call `surface.set_immutable()`.

**Removed:**

* Removed the `unused/` directory which held a collection of unused code that was moved there in 2016.

**Fixed:**

* Fixed some issues in documentation of Surface classes and simplified some of their implementation.

* Fixed typos that lead to runtime errors in rare cases.

**Performance:**

* Improved performance of polygon constructions such as `triangle(26, 48, 75)`.

====================

**Fixed:**

* Adapted to type changes in pyflatsurf 3.7.0.