For 1.4x CVS version
This patch fixes Legacy crashing when using the FS functions to set the floor and ceiling flats. They did not crash when simply getting the current flat. It is only a one letter change for each function (R_ to P_).
It also adds code to set the floortype when the floor flat is changed. Otherwise water sound and splashes are left when changing from FWATER1 or not added when changing to it.