trunk: Change matrix library from using std::exp to exp/expf, for speed...

trunk: Change matrix library from using std::exp to exp/expf, for speed (thanks to tvarog for pointing the issue out); fix to determinize-lattice-pruned-test.cc to work with current code; disallow certain constructors in util/kaldi-table.h that would not work correctly.

git-svn-id: https://svn.code.sf.net/p/kaldi/code/trunk@3445 5e6a8d80-dfce-4ca6-a32a-6e07a63d50c8