Changing format for date_picker so you dont get errors while editing a product. Now its format: ! '%d/%m/%Y' as it should be

Fixes #281
[Turkish] Edited some typos and used more appropriate translations for some terms.

Fixes #282
Changed email-total misspelling.

Fixes #283
[ru] Fix duplication of year in js_format
add correct punctuation at the end of sentences and makes them more explanatory

Fixes #286
Add newline for append_file arguments in add_javascripts (install)

Using append_file without a new line in add_javascripts() causes the
file `all.js' to be saved without a new line at the end and making the
next (different) plugin install fail to write valid data to this file.
For example after installing spree_reviews which appends jquery.rating
to all.js the diff looks like:

   -//= require store/spree_i18n
   \ No newline at end of file
   +//= require store/spree_i18n//= require jquery.rating

Added '\n' suffix for the string arguments of append_file to fix.

Signed-off-by: Ali Polatel <ali.polatel@ozguryazilim.com.tr>
Turkish language pack, edited and updated

Fixes #291
[pt-BR] fixing typos on promotions

Fixes #300

Conflicts:
	config/locales/pt-BR.yml
[de] decimal -> dezimal in german :)

Fixes #299
Fixes wording in the Dutch locale

"state" translates to multiple words in Dutch. Often the wrong words were chosen. Fixed some more translations along the way.
Support config_locale settings in set_user_language override

Fixes spree/spree#3915
Merge branch 'source/2-0-stable' into 2-0-stable

# By Daniel Renner (2) and others
# Via Ryan Bigg
* source/2-0-stable:
  Support config_locale settings in set_user_language override
  Fixes wording in the Dutch locale
  [de] decimal -> dezimal in german :)
  [pt-BR] fixing typos on promotions
  Turkish language pack, edited and updated
  Add newline for append_file arguments in add_javascripts (install)
  add correct punctuation at the end of sentences and makes them more explanatory
  [ru] Fix duplication of year in js_format
  Changed email-total misspelling.
  [Turkish] Edited some typos and used more appropriate translations for some terms.
  Changing format for date_picker so you dont get errors while editing a product. Now its format: ! '%d/%m/%Y' as it should be