Update to support Stan 2.24

• Update functions and signatures to Stan 2.24
• Use the signatures generated by stan-dev/docs#180
• flycheck-stan stanc3 uses --include-paths=. instead of obsolete --include_paths=.
• Minor bug fix in eldoc-stan

Version 10.1.0: Add stanc3 support in flycheck-stan

This version includes an updated version of flycheck-stan that supports stanc3. Two checkers are defined, stanc (old one for stanc2 executable) and stanc3 (new one for stanc3 executable). By default, the updated flycheck-stan expect the executable names in the PATH to be stanc2 and stanc3. Otherwise, the configuration must be specified by setting the flycheck-stanc-executable or flycheck-stanc3-executable variables.

;;; flycheck-stan.el
(use-package flycheck-stan
  ;; Add a hook to setup `flycheck-stan' upon `stan-mode' entry
  :hook ((stan-mode . flycheck-stan-stanc2-setup)
         (stan-mode . flycheck-stan-stanc3-setup))
  :config
  ;; A string containing the name or the path of the stanc2 executable
  ;; If nil, defaults to `stanc2'
  (setq flycheck-stanc-executable nil)
  ;; A string containing the name or the path of the stanc2 executable
  ;; If nil, defaults to `stanc3'
  (setq flycheck-stanc3-executable nil))

Major update with company-stan, eldoc-stan, and flycheck-stan

Here is a screencast showing the new version in action.

This major update adds several new packages:

• company-stan for auto-completion
• eldoc-stan live help for function arguments
• flycheck-stan on-the-fly syntax checking with stanc (Version 2)

Two existing packages have been updated:

• stan-mode for indentation and syntax highlighting
  • Deprecate # comments while handling #include differently
• stan-snippets for function argument completion
  • Support | as an argument separator where appropriate

Other changes are:

• All packages include buttercup automated testing (test-*.el files) to define and ensure their behaviors.
• The minimum requirement for the Emacs version is 25.1.

TODOs:

• Plan for stanc version 3 support.

v9.3.0

• Update stan-mode/stan-keywords-lists.el to support syntax highlighting based for Stan 2.19.0
• Drop obsolete function names such as binomial_cdf_log
• Add new function names such as beta_proportion_rng
• Update, add, or drop snippets following the above changes

v2.3.2

Merge pull request #26 from stan-dev/develop

Develop