Replacing numpy.asarray by theano._asarray when a dtype conversion may be performed, to work around Numpy ticket 870 defect

added option that, bu default, disables linking against -framework. Re-enable, if needed, by setting cmodule.mac_framework_link to True

disable theano.sparse when scipy version is too old. skip the test of theano.sparse in the same condition.

This lower the number of nosetests when we won't use the sparse code.

Commented code that added Mac's Library framework to linking option, because they broke compilation on my machine.

Fixed bug when reading config options of the form obj.subobj (now using only full name instead of name)

bugfix. By default return the numpy blas libraries AND numpy blas library directory to be able to compile correctly.