Need to use the 'use_partial_connect' option in island connect,
so changed signatures of various functions to pass that into and
then down from BM_mesh_intersect (making true for intersect, false
for boolean).
Then fix bm_face_split_edgenet_partial_connect to work when
input edges are not necessarily wire, but at least not in the
face they are being connected in. That caused generalization
of core BM_vert_separate_hflag_wire (which is only used in
this one place in all Blender).
It was only possible to separate all geometry from an intersection or none.
Made this into an enum with a 3rd option to 'Cut', (now default)
which keeps each side of the intersection separate
without splitting faces in half.
- use 'Intersect' prefix for boolean and regular intersection.
hints that they use the same basic logic with different modes.
- 'split by edges' while correct - isn't very descriptive.
Works much the same as intersect operator,
expose as a new operator since for users its quite different.
Access from face menu.
Internally, this adds boolean args to BM_mesh_intersect function.
Was the case of several Mesh operators actually (and probably others, but cannot check
everything). Added `RNA_def_property_float_distance` helper, avoids having to
set PROP_DISTANCE subtype explicitly each time...
Modeling tool to cut intersections into geometry (like boolean, without calculating inside/outside).
Faces are split along intersections, leaving new edges selected.
Access from Face menu.
