Set default field value to current locale
FIX: don't re-enable the locale filter if it wasn't enabled before

This breaks code that tries to get all instances of SiteConfig like:

```
Translatable::disable_locale_filter();
$all = SiteConfig::get();
Translatable::enable_locale_filter();
```

What was happening was that our populateSiteConfigDefaults method was
getting called before the actual data list the users uses above is
created, so it was re-enabling the locale filter before the
augmentDataQuery function was called on the data list created for the
user. Thus, they'd get a locale-augmented query and only get the
SiteConfig for the current locale, and not all as clearly intended.
ENHANCEMENT: better pattern for dis-/enabling locale filter
Mentioning fluent as an alternative solution

hat tip @tractorcow :)
Update index.md
Merge pull request #130 from jthomerson/patch-1

Fix typos in latest commit
Merge pull request #126 from jthomerson/pulls/fix_populate_site_config_defaults

FIX: don't re-enable the locale filter if it wasn't enabled before
Merge pull request #128 from jthomerson/pulls/enhance_disabling_locale_filter

ENHANCEMENT: better pattern for dis-/enabling locale filter
FIX: get_one_by_locale didn't work when filter disabled
Merge pull request #123 from Mark-M/patch-1

Fix Issue #122: Set default field value to current locale
NEW Translatable.enforce_global_unique_urls config setting

See https://github.com/silverstripe/silverstripe-cms/pull/216
and https://github.com/silverstripe/silverstripe-cms/pull/772
for context
Merge pull request #116 from silverstripe/pulls/configure-valid-urlsegment

NEW Translatable.enforce_global_unique_urls config setting
Fixed transifex link
Change dependency versions to work for 3.1.0-rc1.
Test case: class changes propagate to translations when published
Make publishing default locale node faster

When you publish a node in the default locale it calls forceChange to make
every field behave as if it has changed. The problem in Translatable is then
it would think that you actually changed the class of the default locale node
and it would force a change on every translation. This was unnecessary when you
have not actually changed the class name. If you have a great deal of
translations this was causing a significant lag when you publish anything in
the default locale.
MetaTags now includes translated versions of itself including the default translation
SilverStripe coding convetions
Fixed tabs
Fixed tabs