Fix FS_FOpenFileRead corner case

FS_FOpenFileRead is a fairly mental function that changes its return
behaviour depending on whether or not file is NULL or not. It turns out
in the case where file is NULL, we were returning the wrong value when
the file didn't exist.
Fix screwed up whitespace in files.c

Apologies to anyone merging this :(
Fix error message in BG_EvaluateTrajectoryDelta
Merge remote-tracking branch 'upstream/master'

Conflicts:
	code/qcommon/files.c