Make labels clickable and fix spiral vase

1.3.4.20171207

bump version to 1.3.4.20171207

Vase mode and brim lines

• Added vase mode for slic3r
• Added brim lines count for cura

Add perimeters option to advanced tab

Allows for setting perimeters count for slic3r.

Add chop feature

The chop feature lets you chop your object into two pieces, for example, if it's too large to print at once.

Improve object splitting

Splitting of objects is improved with a new algorithm.

Better arranging of parts

• When trying to arrange parts, try more angles looking for the best fit.
• Faster collision detection.

1.2.7.20170511

More performance improvements, especially while loading large STL files.

Faster collision detection

1.2.7.20170508

version 1.2.7.20170508

Performance improvements and better destination filename

• Better destination filename selection when multiple files are selected for printing.
• Using the new Box3 algorithm in more places for better performance

Merge 1.2.6 from upstream + fetaures

• Improved performance by:
  • Using convex hull to calculate bounding box.
  • Memoize overhang calculation.
• More slicing options.