default to vector_origin if we cant get player's eyetrace hitpos

use vector_origin in some other places too

experimental-ish update

replaced right click to snap to grid with right click to drag prop
fixed dupes not saving transparency
hopefully fixed adv dupe not detecting player props
added prop protection to tilebuild props
dynamic snap is now off by default
added server convar to choose how often the prop table is looped through.

r no longer removes props after placement

removed prints

fixed dot staying out on tool change

fixed crosshair not being removed when tool is stripped while active

added add i added and then added its added added, i am very tired

fixed material reverting on spawn

Fixed props not taking damage.

Fix singleplayer right click not working