fixed a bug with sv_gameplayfix_nudgeoutofsolid where the player might

fixed a bug with sv_gameplayfix_nudgeoutofsolid where the player might
get put on the opposite side of a brush because of being very near the
plane that should be used for nudging, which caused it not to be
considered as a nudging plane
added some checks to ensure more consistency on trace direction (should
be able to swap start and end without startsolid trouble, at least less)

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@9537 d7cf8633-e32d-0410-b094-e92efae38249
::stable-branch::merge=5b7ac1706712977bbc0297d2d53294e73574c7cd