rename image-diredx--setup -> image-diredx-setup
Merge branch 'master' into develop

Conflicts:
	image-dired+.el
improve doc
remove redundant autoload form
* change sample of install setting when install not from ELPA.
  To make fast the emacs initialization.

* suppress annoying messages.
refine autoload for ELPA system.
add doc for optional settings
fix doc