Added numpy version check.
Merge branch 'master' of bitbucket.org:vedaldi/matconvnet
Merge branch 'master' of bitbucket.org:ovl/matconvnet
Merge branch 'master' of bitbucket.org:ovl/matconvnet
Merge branch 'master' of bitbucket.org:ovl/matconvnet
Fixes error when no synset is given.

matio cannot export empty dictionary.
doc: fix typo
Makefile and build system: simplifications

The former Makefile was used to create on the fly necessary .cpp files from .cu ones. Now the .cpp files are part of the distribution to avoid confusions.

The Makefile now writes the intermediate build products in matlab/mex/.build. It also does not remove them after the compilation is done, in order to save time when the package is compiled again.
Makefile: use MEX for everything

Avoids invoking NVCC directly. This slightly simplifies the setup.
Makefile: cleanup
manual: small fix
mexutils.h: fix for windows