Add ramp to surfacing utility

[rchouinard]

The current surfacing utility implementation does a plunge to begin the operation, and between layer depths. This works fine for surfacing with square endmills, but won't work with common surfacing bits like this one from Whiteside, which requires a ramp-in if the bit can't start outside of the work piece, as is the case with most spoilboards.

[SienciLabs]

That's a fair point @rchouinard, we'll add it to our todo list

[kglovern]

@rchouinard This change should now be available in the latest release with the surfacing updates. All generated paths now ramp in rather than plunging in to the workpiece.