ClassLoader==null on ClassAsset with class loaded by bootstrap CL

This:

archive.add(new BasicPath("somethingelse"), new ClassAsset(String.class));

...results in:

java.lang.IllegalArgumentException: ClassLoader must be specified
at org.jboss.declarchive.impl.base.Validate.notNull(Validate.java:44)
at org.jboss.declarchive.impl.base.asset.ClassLoaderAsset.<init>(ClassLoaderAsset.java:62)
at org.jboss.declarchive.impl.base.asset.ClassAsset.getStream(ClassAsset.java:71)
at org.jboss.declarchive.impl.vfs.VfsMemoryArchiveImpl.add(VfsMemoryArchiveImpl.java:144)
at org.jboss.declarchive.impl.vfs.VfsMemoryArchiveImpl.add(VfsMemoryArchiveImpl.java:1)
at

This is due to Class.getClassLoader() contract specifying that the bootstrap CL may be represented by null in some (ie. Sun) JDKs.

http://java.sun.com/javase/6/docs/api/java/lang/Class.html#getClassLoader%28%29

Add a test to cover and fix.