Add yas-after-reload-hook' and run it at the end of yas-reload-all'

See https://github.com/pezra/rspec-mode/pull/75 for the discussion leading up to
this change.

ChangeLog

@@ -1,3 +1,8 @@
+2014-01-06  João Távora  <joaotavora@gmail.com>
+
+	* yasnippet.el (yas-reload-all): run `yas-after-reload-hook'.
+	(yas-after-reload-hook): add it.
+
 2013-12-31  João Távora  <joaotavora@gmail.com>
 
 	* yasnippet.el (require): require cl-lib during byte-compilation
@@ -16,3 +21,8 @@
 	* README.mdown: Add Travis CI badge.
 
 	* .travis.yml: new file
+
+
+;; Local Variables:
+;; coding: utf-8
+;; End:

yasnippet.el

@@ -1931,10 +1931,14 @@ loading."
       ;;
       (yas-direct-keymaps-reload)
 
+      (run-hooks 'yas-after-reload-hook)
       (yas--message 3 "Reloaded everything%s...%s."
                    (if interactive "" " (snippets will load just-in-time)")
                    (if errors " (some errors, check *Messages*)" "")))))
 
+(defvar yas-after-reload-hook nil
+  "Hooks run after `yas-reload-all'.")
+
 (defun yas--load-pending-jits ()
   (dolist (mode (yas--modes-to-activate))
     (let ((funs (reverse (gethash mode yas--scheduled-jit-loads))))