[c-c schema] devtools: the output file for cw-ctl schema is not supposed to exist When using the 'file' type, logilab-common errors out if the file doesn't exist. Which, if the option refers to an output file, is not so useful. Use 'string' instead.

[fti] allow usage of custom RQL to fetch entities to index (closes #2410509)

[fti] make db-rebuild-fti accept etypes on command line (closes #2410508)

backport stable

[fti] drop entity cache once an etype is indexed (closes #2410507)

[server/utils] add_looping_task can be used any time (closes #2408814)

[formrenderers] if a tag object gets there, it blows (closes #2410462) - cwtags monkeypatches cubicweb's UStringIO's .write and .getvalue methods - but it cannot monkeypatch list.append ...

[login] redirect to real instance root if no postlogin_path is provided When not postlogin_path is provided, the login form issue a redirect to "/". The instance root may not be at "/" on the server. Then issuing a redirect to "/" send the user to the wrong location. We now redirect to "." which works fine because the "login" controller a direct children of instance root (http://babar.com/instance/login). All other redirection of the login controller use relative path too and then rely on this relative path from the login controleur to the instance root. This mechanism may be considered fragile and may deserve a proper fix. but this is to be discussed and implemented in another changeset.