Deglue navmesh
Remove cpp naming
Refactor path cost into path builder, simplify path creation, optimize path by default
Don't need to check our segment count, our iterator already does this
Multi-goal support
Allow multi-goal to actually work
Remove the need to hold onto engine pointers
Remove some options no one will ever use
Make multi-goal condition more clear
rebase fixups
Merge pull request #226 from Facepunch/deglue-nav
Deglue navmesh & add extra navigation stuff