Updated tex/latex

  * mathug2.sty: new package, based on mathug.sty, currently in
    rudimental stage, allows to typeset greek letters in math in
    following styles: italic (default), normal, bold, bold italic; for
    last three there are defined three separate alphabets;
  * isuth-modules/note.dcf: added package 'vectors' and macro '\Vect' to
    typeset vectors in bold font (very limited application, will fail on
    greek lettes), added three new commands for well-known functions
    that use greek letters (normal font), these commands uses 'mathug2'
    package;
  * isuth-modules/gp-macros.dcf: added command '\SphY' (not best name
    though) to typeset spherical functions, added commands '\bra' and
    '\ket' to typeset traditional bra- and ket-vectors.

Signed-off-by: Vladimir Lomov <lomov.vl@gmail.com>