DJ Matlab / mYm improved version/compatibility support

[ixcat]

Currently mYm check is simplistic against version range and only errors. Since setupDJ installs initial mYm, these things should be expanded to support installations across versions esp. when mYm /DJ pairs might be incompatibile.

To do this:

• Move mym version check in Connection.m into setupDJ() function -
  to ensure earlier detection of mismatched DJ/mYm pairs
• Offer some means to update/correct mYm installation to match mYm to DJ
  e.g. updateMym(versionno) to update to version number or tag or without for default