Implement strand selection visualisation but without any shading.
I think this is not the overlay job to draw the strands shaded.
We can already view the children strands shaded for now but we might add
an option to draw the shaded strand instead of (or in addition to) the
guide strand.
Gets edit more from the current object and displays it as a path.
this is how both hair and particle edit modes are supposed to work.
This only covers path itself, it doesn't do anything like keys
visualization or selection. However, it's already possible to
comb and such.
Only implements particle mode. There are also some settings to
do soft body and cloth. No idea yet what that all is about.
Copy-on-write is not supported either, this is due to some
edit mode ownership problems which are to be addressed from
dependency graph side.
Shading is dead-simple: uses tangent as a color. This is where
i hope to get some help from Clément.
