Admin: the note for an alternative name shouldn't be mandatory

Fixes #1435
Admin: the gender field for a person shouldn't be mandatory
Rearrange blog menu entries
Remove elections banner from home page.
Swap home page election blog entries for week in parliament blog entries.
.travis.yml: Simplify the PostGIS database creation

This switches to using the method suggested here:

  http://docs.travis-ci.com/user/using-postgresql/#Using-PostGIS
.travis.yml: avoid dependency problems that broke PostGIS template creation

Thanks to Matthew Somerville for doing much of the investigation needed
for this problem.  The use of the pgdg and ubuntugis PPAs created an
unresolvable set of dependencies if you wanted both the python-gdal and
a working postgresql-9.1-postgis-* to be installed.  The simplest
solution is to just remove these PPAs before installation, since the
tests all work fine with PostGIS 1.5.3 (the version in base Ubuntu
12.04).

Fixes #1448
Merge branch 'fix-travis-postgis'
Add CSV files for ZA election results.
Add script to import ZA election results.
Add script to end positions which meet the given criteria