Major new features

Add functionality for passing CmdStanFit objects as initial values by @SteveBronder in #937

Other improvements

Add compatibility with CmdStan 2.35 by @andrjohns in #972
Add show_messages and show_exceptions arguments to all methods for controlling output by @andrjohns in #897
Drop RcppEigen dependency, implement basic Eigen -> C++ interop by @andrjohns in #899
Add compatibility with CmdStan 2.34 by @andrjohns in #905 #910
Add a format argument to the unconstrain_draws() method to specify draws format of return by @andrjohns in #886
Align cmdstanr EBFMI diagnostic threshold with CmdStan by @andrjohns in #892
Add global option cmdstanr_print_line_numbers to add line number to model printing by @sbfnk in #967
Add new CmdStan arguments save_metric and save_cmdstan_config by @venpopov in #932
Add documentation for CmdStanR global options by @jgabry in #951
Add documentation for how to obtain structured output similar to rstan::extract() using a combination of cmdstanr and posterior by @jgabry in #955
Added coercion generics for CmdStanFit objects by @gowerc in #943
psis_resample and calculate_lp arguments added to Pathfinder method by @SteveBronder in #903
Documentation and tests for LOO method updated by @jgabry in #923
Global option cmdstanr_warn_inits added to disable warnings about partially specified initial values by @jgabry in #913
Updates to MCMC output_dir documentation by @jgabry in #929

Fix broken link in OpenCL documentation by @eipi10 in #908
Fix a minor typo in the README by @jgabry in #911
Make exported RNG functions respect changes to R's seed by @andrjohns in #973
Optimisations for model methods functions by @andrjohns in #960
Bugfix for passing function for initial values with Pathfinder method and default num_paths by @andrjohns in #964
Continue with compilation if compile_stanalone=TRUE but no functions are found by @jgabry in #956
Update tests and CI for compatibility with MacOS ARM64 by @andrjohns in #958
Fix handling of inv_metric argument with only 1 parameter by @venpopov in #935
Fixes for compatibility with RTools44 by @andrjohns in #952 #959

Full Changelog: v0.7.1...v0.8.0