Bump version to 0.104.8 and update change log

CHANGELOG.org

 * Release 0.104.x
+** 0.104.8 (2015/12/16)
+*** Hotfix
+- Revert removal of fancy battery mode-line indicator.
 ** 0.104.7 (2015/12/15)
 *** Distribution layer changes
 **** Spacemacs

init.el

@@ -14,7 +14,7 @@
 ;; (package-initialize)
 
 (setq gc-cons-threshold 100000000)
-(defconst spacemacs-version          "0.104.7" "Spacemacs version.")
+(defconst spacemacs-version          "0.104.8" "Spacemacs version.")
 (defconst spacemacs-emacs-min-version   "24.3" "Minimal version of Emacs.")
 
 (defun spacemacs/emacs-version-ok ()