Merge pull request AsyncHttpClient#40 from gailh/MacUploadLargeFileIssue

Upload large file issue

Author: jfarcand

src/main/java/com/ning/http/multipart/MultipartBody.java

@@ -458,7 +458,7 @@ private long handleFilePart(WritableByteChannel target, FilePart filePart) throw
                         if (nWrite == 0) {
                             logger.info("Waiting for writing...");
                             try {
-                                fc.wait(1000);
+                                fc.wait(50);
                             } catch (InterruptedException e) {
                                 logger.trace(e.getMessage(), e);
                             }