Name filters, line ending preservation, etc.

Added a few new features:
- Name filters for the 'find' command. Allows you do to a selective
  correction to say, .cpp and .h files only. (-N <filter> switch)
- Told sed to not mess with line endings (-b). Useful for Windows (MinGW)

Usage example:

./misspell_fixer.sh -f -n -r -N *.cpp -N *.h /c/foo/bar/baz