Document necessary location of slug column (resolves #293)

This adds a point of clarification in the rdoc and inside the globalize module itself to point out that the slug column must be present on the translation table, not the primary model table itself. It also (real friendly-like) corrects some faulty parallelism.
Merge pull request #308 from robyurkowski/master

Document necessary location of slug column with Globalize
Clarify globalize slug documentation further

It should now be clear that both the model's table and the model's
translation table must have a slug field, and the model must declare the
slug field translatable.
Merge pull request #309 from robyurkowski/master

Clarify globalize slug documentation further
Fixing the mocha load order so Travis builds work again.
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