+ <rewbs> Added release section to volume envelope (see: http://openmpt.xwiki.com/xwiki/bin/view/Manual/InstrumentReleaseEnvelope). IT only.
  . <rewbs> Overflow fixes in file loading functions (see: http://aluigi.altervista.org/adv/mptho-adv.txt)
  . <rewbs> Greyed out irrelevant items in the orderlist context menu.


git-svn-id: https://source.openmpt.org/svn/openmpt/trunk/OpenMPT@163 56274372-70c3-4bfc-bfc3-4c3a0b034d27