[CB-861] Header support for FileTransfer download

Added support for an optional options object as the final arg. Currently only handles the options.headers object (as per the issue).

`FileTransfer.download(source, target, successCallback, errorCallback, trustAllHosts, options)`

This is needed for using FileTransfer.download with Basic Authentication, etc. Sadly since Android 2.x doesn't support XHR2, this is needed in FileTransfer.

I have only added support to Android and iOS (see other PR's).
Fixed CB-2620: console.log prints only the first argument on Xcode console
[CB-2621] Added OS X platform
Added .gitignore so I can add an empty directory to git
[OS X] Fixed plugin callbacks not being called
Add readAsBinaryString and readAsArrayBuffer to FileReader
[WindowsPhone] CB2592, remove CordovaCommandResult
CB-2595: Prompt mode emits confusing log message
When Android switches to PROMPT mode, the log message causes confusion
for users, especially for those having to support Gingerbread. It is tough
though since it can be a legitimate error when restoring state.
[WindowsPhone][CB-2592]Remove global callbacks for media
[CB-1933] Changed button labels to an array.

This allows commas to be included in button label text.
The use of comma-separated strings for this purpose is deprecated.
[CB-1686] Added a camera direction option.
Merge pull request #3 from purplecabbage/CordovaMediaonStatus

[WindowsPhone][CB-2592]Remove global callbacks for media
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/cordova-js
Always pass slice parameters to FileReader
[android] Add support for binary strings to the bridge
[webos] modulemapper refactor for platform plugins.
Add scripts/plugin_loader.js, which runs after bootstrap.

This code does an XHR for cordova_plugins.json. If it finds the file, it
will load the plugins specified in it. If the response is empty or the
XHR fails, it does nothing.

This creates a new onPluginsReady event that fires either when the
plugins are all loaded or there are no plugins to load. The bootstrap is
waiting on this now, as well as onDOMContentLoaded and onNativeReady.
[CB-52] API: FileTransfer - Basic Authentication

commit 00a7ca15142804d7b8f0c8d8ade0088ba34b3015
Author: Shazron Abdullah <shazron@apache.org>
Date:   Wed Mar 20 10:03:25 2013 -0700

    [CB-52] Fix whitespace issues

commit e72a998830a5e5dba5bd9694affca5544d8fad6c
Author: Shazron Abdullah <shazron@apache.org>
Date:   Wed Mar 20 09:57:48 2013 -0700

    [CB-52] API: FileTransfer Download - Basic Authentication

commit 18ad146a4ec3411bbf944bcdb99e067456ba6cb3
Author: Shazron Abdullah <shazron@apache.org>
Date:   Tue Mar 19 17:06:19 2013 -0700

    [CB-52] API: FileTransfer Upload - Basic Authentication
[CB-2308]: Add loaderror channel to InAppBrowser Plugin
CB-2679 Add prompt to Notification API for js

- added a native prompt method to Notification API
- added 2 jasmine unit tests for new prompt method
- note that the prompt method expects an Array for buttonLabels