Upgrade the Marlin renderer in Java2D

The Marlin renderer integrated in OpenJDK9 (JEP 265) corresponds to Marlin 0.7.4.
This enhancement for JDK10 brings changes provided by Marlin 0.7.5, already integrated in OpenJFX9, including:
- added the double-precision variant (DMarlinRenderingEngine) for higher accuracy (double vs float)
- MarlinFX backports (Dasher, Stroker changes from OpenPisces)
- Improved MarlinTileGenerator to efficiently handle asymetric tiles (W x H) with almost full / empty fills
- higher precision of the cubic / quadratic curve conversion to line segments (but up to 10% slower); use the following properties to revert to the previous quality settings: -Dsun.java2d.renderer.cubic_dec_d2=2.5 -Dsun.java2d.renderer.cubic_inc_d1=1.0 -Dsun.java2d.renderer.quad_dec_d2=1.0
- syntax / comment corrections

The default RenderingEngine will use the double-precision variant.