[feature] redirect to the page asked in the first place
ex :  http://cozy/path?a=b&c=d#h
redirects to http://cozy/login/path?a=b&c=d#h
and after login to http://cozy/truc?a=b&c=d#h

NEED TESTS
redirect query string too
fix tests
Merge pull request #18 from mycozycloud/feature/redirectlogin

Feature/redirectlogin