VIS phase minor switches edit

-fast
Only calculates rough visibility data. Quick and dirty, not actually useful for VIS purposes.
-hint
Will merge the bsp leaves (except for hint portals) before calculating the visibility list.
-merge
Will merge the bsp leaves before calculating the visibility list.
-nopassage
Disables the passage visibility algorithm. Passage VIS is a bit faster and tighter than the old algorithm.
-nosort
Disables the sorting of portals by complexity. Sorting speeds up visibility calculations.
-passageOnly
Will use the passage visibility algorithm only.
-saveprt
Disables the automatic deletion of the .prt portal file after VIS finishes.
-v
Enables verbose mode. Always use this.