IDE-1671 fix spelling
IDE-1671 remove trailing whitespace
IDE-1554 fixed a layout template
IDE-1653 corrected the editor validation of filter-class in portlet.xml
instead of implemnting all interfaces, just need to implement one of them
IDE-1554 source refactoring
many overlaps about adding templates in AddLayoutTemplatesFactory and AddLayoutTplOperation,
extract them and remove the redundant ones.