Update README.md

Clarification to save the next guy some time.
Merge pull request #147 from jfeltz/patch-1

Update README.md
typo (issue #145)
Don't delay Emacs when Eclim is not running

* eclim-problems-highlight: Change eclim--file-managed-p to eclim--accepted-p, move outside save-restriction

* eclim--accepted-p: Check for accepted filename before trying to execute an eclim process; this is
  significantly less expensive
Normalize filenames in "problems" output, since drive letter comes back in wrong case on Windows