Added minibatch support to MarginRankingCriterion and PairwiseDistance.
remove WeightedMSECriterion test since it fails with an unknown module
Document qt terminal for gnuplot
Add support for PDF in figprint if gnuplot supports

Gnuplot support for pdf is enabled in homebrew with
`brew install gnu plot --pdf``
Document pdf for figprint
Document svgfigure

It was undocumented, yet can be useful.
Send error if gnuplot does not have pdf support
Add function pdffigure()
Document pdf possibilities
Document in main description, too
Fix typo in description of eps terminal
move k into thread private loop
move index declaragtion into pragma
fixed a bug in CUDA norm
add 3D max pooling
add 3D convolution documentation
added strict c89 flags
fixed cuda flags issue
C89
avoid paths being compiled with C89 flags: some compilers fail.