bugfix for searching acts by author (person)

apparently, if prepare_person returns a list it works, while if it
returns a set it does not

fixes #363
Deployment checks
Added log directory (just to avoid errors during django-admin.py syncdb
small fixes

in order not to show the link between mayor and council group, do not insert
any instance of GroupCharge for the mayor

fix #456
see #455 TODO verify the vote import does not stop working
Merge branch 'dev-senigallia' of https://github.com/openpolis/open_municipio into dev-senigallia
fix sorting by presence

we forgot to parseInt(...) a string representation of present. this lead to
lexicographic ordering, instead of numeric ordering

fix #454
parameterize the contacts email address

fix #395
small fixes
refined act import procedure

act subscribers are reset, every time an act is imported from
XML: this assumes that the information in the XML is
complete
drop term Emendation from XML schema. replaced with Amendment
bugfix in importing subscribers
Webmaster info kept from settings to render notification emails. (see
#405)
related news filter is now active on modified field instead of created
public_date and public_idnum override for approved deliberations
search index for act's pub_date now considers approval dates for deliberations
fix data import
access to _choice_dict private attribute modified
error when extracting textual content from doc files, trapped
fix taxonomy detail view

close #376
allow to configure webmaster info in contacts and privacy pages

close #395