keyboard shifts again

hi,

keyboard shifts are broken apparently: the formulas are not parsed correctly anymore (e.g. "1<<2" results in "Malformed expression"). I can't build all previous versions on my machine and can't tell you which commit broke it, but 6b24c91d3aa81fdb99500c8c2c12f830fabaefb6 removed some parts of my patch. OTOH all needed parser/lexer code is not touched by it. Most of my changes that were deleted by that commit were reapplied in 4531aea8ae8b2253218e0c6734618823003d2408. The only yet missing parts are the tooltip characters which are included in this pull request, but of course they don't fix the parsing problem.