[devtools/testlib] Port CubicWebTC.view() to py3k testlib.TestCase.set_description's argument will eventually be printed out to sys.stdout/stderr. On python 2, this object takes bytes-like objects (eg, str) whereas python 3's takes unicode-like objects and handles the encoding on its own. Thus the 'str' type can used in both versions to eventually display the description on screen.

addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile