Remove unsused code (minor)

James Bergstra added the assert in 2010; 
it was not triggered since then so maybe 
this code can finally be removed?
Fix missing variable renames
Fix when scan sequences are provided as a 1-key dict

Add test for that case
Declare variable before using it
Simplify optimization and remove unreachable code.

After additional checks introduced in gh-1578, some code that was
potentially problematic became unreachable. This commit removes it.
This makes gh-1345 obsolete.
Address the case where sequences are provided as dicts.
Make the op_lifter take a list and lift again the Sum op.

Add test for it.

Do not include now the Prod op as there is failing test.
Remove compilation warning.
NumPy 1.8 changed a private interface, but the official interface output useless stuff to the user.

Try to use the old interface and silence part of the printed stuff.
Update NEWS_DEV.txt
pep8
update .mailmap
Add contributor list.
update .mailmap
Allow tests outside this repo to reuse our tester
Update NEWS_DEV.txt
Doc Anaconda Installer don't work anymore on windows.
remove lgpl code
Better error message.
Better error message