Revert back to encodeURL() for images not part of theme
Bug fixed: B65-ZK-1671
- if user specified theme-provider-class in metainfo/zk/zk.xml,
  it may get overridden by StandardThemeProvider, depending on
  jar file loading order
Merge branch 'B65-ZK-1671' of git://github.com/leeyt/zk