Rectilinear-Gapfill edition

merged against slic3rPE1.42.0-rc1 (the may 15th master merge)

new

• rectilinear with gapfill option. A better way to cover small strange areas.
• improve the precision from 25bits to 40bits
• get the test framework from slic3r and began to include some tests.

bugfixes

• #58 and #60

know issue

• can crash at gcode preview.
• localization problem

I didn't had all the time i wanted to test this version. But I can't let it slide further in time.