Fix PR gh-90

If cause import crash in some cases.

When device=cpu and force_device=True, force that we disable the gpu.

Make inc/set_subtensor work on output of take.

Err msg

fix reload and better error message

At worst, it would cause crash.

Add new commands to theano-cache.

"theano-cache basecompiledir purge" is useful when the kernel or Python
version changes, as cache directories accumulate.

Always put arch bitwidth in cache

Multiple mode

Also move local_bitwidth to gof/compiledir, import it directly in
theano.gof, and use the latter path.

This is to avoid loading modules compiled with one architecture from a
Python with a different one.

mrg multinational grad

Fix march on windows

Travis ci scipy

don't use the equivalent flags for -march=native for llvm 

This remove a warning introduced in gh-1265.