Add support for slashes in the filenames (directories)

Docs: https://www.backblaze.com/b2/docs/string_encoding.html

Author: Bjørn Håkon Noss

src/main/java/synapticloop/b2/request/B2UploadFileRequest.java

@@ -114,11 +114,7 @@ public B2FileResponse getResponse() throws B2ApiException {
 			headers.put(HEADER_CONTENT_TYPE, mimeType);
 		}
 
-		try {
-			headers.put(HEADER_X_BZ_FILE_NAME, URLEncoder.encode(fileName, VALUE_UTF_8));
-		} catch (UnsupportedEncodingException ex) {
-			// should never happen
-		}
+		headers.put(HEADER_X_BZ_FILE_NAME, Helper.urlEncode(fileName));
 
 		headers.put(HEADER_X_BZ_CONTENT_SHA1, Helper.calculateSha1(file));
 

src/main/java/synapticloop/b2/util/Helper.java

@@ -63,7 +63,7 @@ public static String calculateSha1(File file) throws B2ApiException {
 	 */
 	public static String urlEncode(String url) {
 		try {
-			return java.net.URLEncoder.encode(url, UTF_8);
+			return java.net.URLEncoder.encode(url, UTF_8).replace("%2F", "/");
 		} catch (UnsupportedEncodingException ex) {
 			// highly unlikely
 			return(url);