* Tuned various details of TOV/tidal deformability computation to improve accuracy
  and robustness
* Improved error model for TOV solutions, calibrated with many tests
* One can now specify the desired accuracy for TOV properties (no more exposure to
  accuracy-related technical parameters of the implementation)
* Finding stable TOV branch now more robust in corner cases
* Fixed issue #34. Tidal deformability now accurate also for very small compactness.
* Added small collection of EOS files from nuclear physics
* Documentation: corrections and improvements
* Use keyword-only arguments in parts of Python API to prevent common typos

Backward-incompatible interface changes for TOV solvers, TOV accuracy
specification, and NS TOV branch finding.