Don't use C-x SPC as it's used in Emacs 24.4 by default for rectangular selection
Change C-c SPC to C-c j to avoid a conflict in org-mode

In org-mode C-c SPC is bound to `org-table-blank-field`
Bind ace-jump-mode to s-. as well
Mention guru-warn-only
Merge branch 'master' of github.com:bbatsov/prelude