change index variable name
remove settings.qutip_graphics flag and conditional imports of matplotlib based on DISPLAY variable, to allow head-less generation of graphics. if matpotlib is unavailable, a warning is given, but no failures until a function that actually uses matplotlib is called
move Arrow3D into conditional matplotlib try statement
Merge pull request #235 from jrjohansson/fix-headless-graphics

fix headless graphics
added missing import
added unit test for operator_to_vector failure reported in #217
fixed bug in operator_to_vector / vector_to_operator
new fix for #237
Merge pull request #1 from qutip/master

Pull from upstream
First attempt at making super_tensor work for states. See #238.
Merge branch 'master' of github.com:cgranade/qutip

Conflicts:
	qutip/permute.py
	qutip/tensor.py
	qutip/tests/test_qobj.py
Forgot an import in new unit test.
Fixed bug in permute. Unit tests now pass locally.
Merge pull request #240 from jrjohansson/fix-issue-237

Fix issue #237
replace double .H with double .T as @cgranade suggested
Changed type == 'super' to issuper, etc.
Merge pull request #242 from jrjohansson/fix-issue-237

replace double .H with double .T as @cgranade suggested
Added composite() as discussed in #241.
Merge pull request #241 from cgranade/master

Add operator-ket and operator-bra support to super_tensor.
raise errors if zvode fails in mesolve and sesolve