stream cleanups


git-svn-id: http://svn.code.sf.net/p/sauerbraten/code@4978 07af1644-1164-4067-b897-63bf4dc9b748
streambuf cleanup


git-svn-id: http://svn.code.sf.net/p/sauerbraten/code@4979 07af1644-1164-4067-b897-63bf4dc9b748
getstring/filtertext cleanup


git-svn-id: http://svn.code.sf.net/p/sauerbraten/code@4980 07af1644-1164-4067-b897-63bf4dc9b748
listdir/listfiles cleanup


git-svn-id: http://svn.code.sf.net/p/sauerbraten/code@4981 07af1644-1164-4067-b897-63bf4dc9b748