[ext/rest] fix docstring of rql_role()

[web application] Fix missing self. in error_handler

[ldapfeed] all options of a source should be in the same group, else you get AssertionError on c-c add-source. Closes #2538398

[sources] fix classes that inherit from AbstractSource (closes #2718669)

[login] don't redirect to http url if we allow anonymous on https Closes #2583913

Correct typo in example

[testlib] make test_view load the json data Closes #2721472

[etwist] Properly escape traceback output (closes #2712042) Stop using StringIO in the process as well.

[dbapi] Stop shadowing exceptions in get_repository() (closes #2710515) Exceptions are already handled higher up in the stack so there's no reason to handle them here. Furthermore, non-ConnectionError exceptions would get hidden, making debugging harder.

[cwvreg] complete cw.web.uicfg cleanup callback (closes #2718217) 1dd655788ece introduced insufficient backward compat support When cubes directly import uicfg from cubicweb.web (or uihelper) this also creates a reference in the parent cubicweb.web namespace. This must be cleaned up as reloaded cubes will take back this reference and the old versions of its appobjects.

[book] fix typo. remove spurious `i`

[towards py3k] fix bug introduced by 0bb18407c053

[doc] Book entry for the undo functionnality.

[toward py3k] rewrite has_key() (part of #2711624) The `has_key` method is not in Python3K but dict supports __contains__ check for ages.

[toward py3k] rewrite dict.keys() and dict.values() (part of #2711624) Python 3K will only expose iterators. http://docs.python.org/3.0/whatsnew/3.0.html#views-and-iterators-instead-of-lists

[toward-py3k] rewrite to "except AnException as exc:" (part of #2711624) The older form is not necessary since we dropped python 2.5 compability. This will help Python 3.3 experimentation.