Add probe_pt(), useful for auto bed leveling
Refactor 3-point auto bed leveling to use probe_pt()
Refactor 'accurate' auto bed leveling to use probe_pt()
Merge pull request #774 from MissionSt/cleanup/probe_pt

Refactor of z probing for auto bed leveling
Use language.h instead of English literals for "bed"
Merge pull request #775 from MissionSt/lang-fix/bed

Use language.h for "bed"
Merge branch 'Marlin_v1' into MakerFarm_i3