2nd part of streamline patch from oshima@eng.niigata-u.ac.jp

add back/forward step buttons (patch from oshima@eng.niigata-u.ac.jp)

select time step

support groups of nodes for physical groups (gor Guillaume)

implemented "Save groups for nodes" for unv

format needs to be verified

- prepare group of nodes in UNV (for Guillaume)
- prepare delaunay for connected volumes
- test 2nd patch from Michel for phase1() extrusion

dos2unix

add suport for Log10 in matheval

re-add SphericalRaise: it's easier than Warp (it's reversible!) to plot
radiation patterns

add shortcut to draw outines

remove all annoying 3rd level menus

- new alt+r shortcut to switch range modes

new gui for plugins (much better IMHO!)

add test version of fourier model

bof

- polished mesh option strings in gui
- merged modified extrusion patch from <mi.benham@free.fr>