Bugfix: crash when reading/writing files to paths containing non-ASCII characters on Windows. #651 #865
offset miter limit to 3 - 801 828 836 851 875 - spikes and pimples

Was set to 10 to address 801. Setting to 3 has the same effect for 801,
and avoids spike artifacts that are likely causing "spike and pimple"
problems in the referenced issues.
extraneous fill against sloped walls with fill every N layers #834

Polygons used for N x depth fill surfaces need to be offset
by flow spacing before they are reused to clip lower fill surfaces.
Otherwise thin fill sections remain on clipped layers against sloping
walls, and the N x depth fill collides with them.
Ignore perimeter_acceleration and infill_acceleration if their values are 25 and 50 to handle legacy configs gracefully.
use infill flow spacing, not perimeter, for combine_infill() clip offsets
Merge branch '834-every-n-fill-frags' #834
per-thread clipper object for parallel support generation #888
Don't fill gaps if fill density is 0. #915
Enable cooling by default
Require Math::Clipper 1.17
Increase default value for retract_length_toolchange
Interface support layers were clipped badly.  Also, reduce simplification of the clipping boundaries. #583
Update retraction.t to work with two-phase retractions (triggered by changing the default retract_length_toolchange to something greater than 3)
Fixed regression introduced in 4d8757bf5da269b35133c6d6be3f06c3465b9ec9 causing crash during support material generation
Fix help text s/perimeters-/perimeter-/. #917
Add Mike Sheldrake in the About window
New G-code flavor for Sailfish (thanks to fros1y for working on it). #826
Change toolchange and G92 E0 order for makerbot and sailfish G-code flavors. #855
Releasing 0.9.8
Bump version number