Removed or begin in favour of ||= do

This uses one less block than previously.
update_attribute is deprecated; using update_attributes instead.
Merge pull request #316 from norman/optimisations

Removed or begin in favour of ||= do
Fix minitest version to 3.2.0

Minitest 3.3.0 was released a few days ago and currently dies with:

```
/Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:826:in `block in _run_suite': undefined method `run' for #<ConfigurationTest:0x007faf1d5835f8> (NoMethodError)
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:818:in `map'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:818:in `_run_suite'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:805:in `block in _run_suites'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:805:in `map'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:805:in `_run_suites'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:778:in `_run_anything'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:967:in `run_tests'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:954:in `block in _run'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:953:in `each'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:953:in `_run'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:942:in `run'
  from /Users/norman/.rvm/gems/ruby-1.9.3-p194-perf/gems/minitest-3.3.0/lib/minitest/unit.rb:700:in `block in autorun'
rake aborted!
Command failed with status (1): [/Users/norman/.rvm/rubies/ruby-1.9.3-p194-...]
```

I don't have time to track this down right now, will check later if this is a
bug in our code or theirs.
Updated changelog
Fix minitest version in all Gemfiles
Name anonymous class to fix marshalling.

Resolves #314
Update changelog

[ci skip]
Add @parndt to authors

[ci skip]
Set release data

[ci skip]
Correct missing post instance variable in the docs. (ht: aklein-dex)
Uses LEN when using sqlserver as connection source

SQLServer does not support the LENGTH function, but has the same functionality implemented with LEN.
This change detects if the 'sqlserver' connection adapter is being used, and changes the
function accordingly.
Fix relation code to support Rails 3.2.9.rc1

See issue #332
Bump version and update changelog

[ci skip]
Merge pull request #330 from btrepp/master

Fix LENGTH undefined in microsoft sqlserver
Fix broken TravisCI image
Merge pull request #346 from andyw8/master

Fix broken TravisCI image
Fix tiny typo in readme
Merge pull request #347 from qnm/master

Fix tiny typo in readme
Fix LENGTH undefined in slug history for microsoft sqlserver. fix #330