fix precision issues with tqaa reprojection


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1578 b412e182-2ed4-4078-95c4-27dc59f57fa9
vec4d -> dvec4


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1579 b412e182-2ed4-4078-95c4-27dc59f57fa9
muld usage


git-svn-id: svn://svn.tuxfamily.org/svnroot/tesseract/main@1580 b412e182-2ed4-4078-95c4-27dc59f57fa9