Add options param to Library func with option to disable appending on…

… library extension

fixes #257

lib/library.js

@@ -31,12 +31,21 @@ var EXT = Library.EXT = {
  * ForeignFunction.
  */
 
-function Library (libfile, funcs, lib) {
+function Library (libfile, funcs, lib, options) {
   debug('creating Library object for', libfile)
 
+  if (!options) {
+    options = {}
+  }
+  options.appendExtension = typeof options.appendExtension === 'boolean' ? options.appendExtension : true
+
   if (libfile && libfile.indexOf(EXT) === -1) {
-    debug('appending library extension to library name', EXT)
-    libfile += EXT
+    if (options.appendExtension) {
+      debug('appending library extension to library name', EXT)
+      libfile += EXT
+    } else {
+      deug('appending of library extension has been disabled')
+    }
   }
 
   if (!lib) {