3.137badded: import/export of upcoming MAME flag "ismechanical"
setinformation's 'Select Sets' supports variable %M=1 to mark mechanicals
Split system default path "Standard" into "Standard" and "Mechanical", ie you
can split mechanical sets in an own path. Note, if a mechanical set is also using a bios
the belonging bios path is used since that binding got a higher priority
added: scanner advance option to keep disabled sets as unneeded (instead of ignoring them)
misc: changed a bit the show missing behaviour of sets which only consist of nodumps and samples
misc: correct handling of not possible profile renaming of hyperspin/offline/software list dats
misc: for now, stop parsing dats if 1st closed main element is found
misc: supporting chds in mess software lists
