Fixes issue for adding Native Library files to APK

Currently the code for include Native Libraries does not work. This pull request fixes the issue.

<H2><b>Here is an example how to added the native libriaries</b></H2>

1)  Add you libraries to the <b>appinventor\lib</b> folder

<b>Example:</b>

	appinventor\lib\sphero\RobotLibrary.jar
	appinventor\lib\sphero\armeabi\libachievement_manager.so
	appinventor\lib\sphero\armeabi-v7ai\libachievement_manager.so



<br>2) In the file <b>appinventor\buildserver\build.xml</b> add the native library

<b>Example:</b>

	<copy toFile="${classes.files.dir}/RobotLibrary.jar" file="${lib.dir}/sphero/RobotLibrary.jar" />
	<copy todir="${classes.files.dir}/armeabi">
		<fileset dir="${lib.dir}/sphero/armeabi" includes="*.so" />
	</copy>
	<copy todir="${classes.files.dir}/armeabi-v7a">
		<fileset dir="${lib.dir}/sphero/armeabi-v7a" includes="*.so" />
	</copy>
    

<br>
3)  In the component file <b>appinventor\components\src\com\google\appinventor\components\runtime\mrSphero.java</b> add the <b>@UsesNativeLibraries</b> annotations as shown below

<b>Example:</b>

	@DesignerComponent(version = 1,
		description = "Component to control Sphero",
		category = ComponentCategory.USERINTERFACE,
		nonVisible = true,
		iconName = "images/mrSphero.png")
	@SimpleObject
	@UsesPermissions(permissionNames = "android.permission.BLUETOOTH_ADMIN, android.permission.BLUETOOTH")
	@UsesLibraries(libraries = "RobotLibrary.jar")
	@UsesNativeLibraries(libraries = "libachievement_manager.so" ,
							v7aLibraries = "libachievement_manager.so")
	public class mrSphero extends AndroidNonvisibleComponent
Just want to make sure that the problem was not somewhere else (like in the other changes you made). It was not compiling? or not building apps?