release/v4.5.0: updating version numbers

RELEASE-NOTES.txt

@@ -1,5 +1,29 @@
 Stan Math Library Release Notes
 
+======================================================================
+v4.5.0 (21 November 2022)
+======================================================================
+
+ - Added the generalised hypergeometric function. (#2510)
+ - Added var<Matrix> overloads for  `pow()`, `owens_t()`, `log_inv_logit` . (#2546, #2787, #2806)
+ - Add tuple overload and cleanup code for promote_scalar. (#2706)
+ - New gradient function allows evaluated gradient to be stored into an array, enabling memory reuse when stan/math called via a FFI. (#2743)
+ - Added function for casting `double` and `std::vector<double>` types to `int` and `std::vector<int>` types(#2771)
+ - Added `hypergeometric_2F1` function. (#2792)
+ - Fix bug with vectorised `pow()` incorrectly forcing `Eigen::Matrix` return instead of `Eigen::Array`. (#2793)
+ - Exposed the `hypergeometric_3F2` function and improved its numerical stability. (#2797)
+ - Fixed incorrect return from `log_inv_logit_diff` with positive infinity first argument. (#2798)
+ - Added reverse-mode specializations for `fft2` and `inv_fft2`. (#2800)
+ - Removed the cause of the out-of-order initializer compiler warning.(#2808)
+ - Vectorized `atan2()`.(#2812)
+ - Added `complex_schur_decompose_t` and `complex_schur_decompose_u`.(#2814)
+ - Vectroized the `conj()` function. (#2817)
+ - Stan's algebraic solvers now support variadic arguments. (#2820)
+ - Fixed forward mode autodiff for FFT functions. (#2821)
+ - Added `log_sum_exp_signed` function for computing `log_sum_exp` while respecting signs of arguments and tracking the sign of the result. (#2829)
+ - `stan_print` can now print std::tuple types. (#2835)
+ - `stan::math::minus` can now accept `std::vector`. (#2840)
+
 ======================================================================
 v4.4.0 (1 July 2022)
 ======================================================================