Trim trailing whitespace and add EOL to end of files for cleanliness and easier diffing.
Minor bug fixes and cleanups:

  * Add format attribute to printf style functions and fix the errors found
  * Remove double-underscore prefix from config struct name, identifiers
    beginning with two underscores are reserved for compiler use
  * Add /usr/include/libev to default include path (used on Fedora & RH)