fixup to use register_javascripts() to prevent dupicated scripts
fixup regression by the commit "support nested pre blocks {{{...}}}"
fixup old table parser bug.
check blockquote separatly
fixup old userform action bug
support join agreement form
update po messages
FoldingProcessor: support opened folding area

 * open option added to support opened folding area (suggested by rhealovekr)
 * additional class name support added
 * set default title "More"
 * and refactoring
bump up version to 1.2.3-RC2
Parsedown added
Parsedown processor: support [[WikiLinks]]