Fix NPE in namespace equals()
Don't falsely break on end namespace tag

A binary XML file may have multiple namespaces defined, which are typically
nested. If namespace A wraps namespace B, then end of namespace B should
not trigger stop of XML serialization.
Properly escape strings in XML attributes

String refernces are localized and defined as element text bodys.
XMLTranslator inlines these values into binary XMLs (e.g. the manifest) as
attributes. This may result in malformed XML, e.g.:
  <application name="Hello & Goodbye" />
This commit will use Apache Commons Lang3 to properly escape attribute
stirngs.
Merge pull request #17 from soundmonster/master

Proper namespace handling