Remove cider-repl-mode from rainbow-delimiters-ignore-modes.

CIDER has been updated and doesn't need this workaround anymore.
Wrap the font-lock-fontify-buffer call with with-no-warnings.

font-lock-fontify-buffer is for interactive use only in Emacs >= 24.5.
Don't enable in Completion List Mode
Don't enable in special RefTeX modes
Merge pull request #38 from lunaryorn/patch-1

Don't enable in reftex-toc-mode
Deprecate global-rainbow-delimiters-mode.
Remove global-rainbow-delimiters-mode from installation instructions.