Added option to allow disabling registration
Fix option to allow disabling registration
Fix delegations after base_url change

Addendum to ad4c95357faeea8c96f28346fbde2f808162c290
pep8
simplify freshness calculation
fix time interval constants

* 2 days have 48 hours, not 36
 * precalculate number of seconds
Take negative ratings into account for mixed proposal sorting

Previously, the mixed proposal sorting only took supporting ratings into
account. It now uses the difference of supporting and rejecting ratings.

This is a quick fix, but generally this sorting method should be
reinvestigated (see #170).
Move norms behind milestones in instance navigation
Disallow multiple usernames with only case differences (fixes #171)

This only avoids creation of duplicate users with the same username in
different cases, but doesn't make usernames case insensitive altogether.

This also doesn't change existing installations, which already have such
duplicates.
Fixed details
Merge pull request #166 from carschroeder/feature-allow-disabling-registration

Added option to allow disabling registration
Exported PROPOSAL_SORTS to the controller in order to implement a default sorting order feature.
New feature: default sorting order for proposals
New feature: default sorting order for proposals 2
Merge remote branch 'upstream/develop' into feature-default-sorting-order
Feature: default sorting order
Feature: default sorting order
Move default into factory
Merge pull request #1 from phihag/feature-default-sorting-order

Move default into factory
Fixed all little issues