translations: Transifex integration

* Add Transifex configuration file
* Cleaup translation files to conform to
  Transifex rules to allow upload.

Tuleap #18
Change-Id: I3fbce0120a690263843c733533b0932e71f3d69a
diff --git a/ring-android/app/src/main/res/values/strings_account.xml b/ring-android/app/src/main/res/values/strings_account.xml
index ff09f59..cedd0e5 100644
--- a/ring-android/app/src/main/res/values/strings_account.xml
+++ b/ring-android/app/src/main/res/values/strings_account.xml
@@ -56,7 +56,7 @@
     <string name="account_hostname_label">Hostname</string>
     <string name="account_username_label">Username</string>
     <string name="account_password_label">Password</string>
-    <string name="account_optionnal_category">Optionnal Settings</string>
+    <string name="account_optionnal_category">Optional Settings</string>
     <string name="account_useragent_label">User Agent</string>
     <string name="account_autoanswer_label">Auto Answer</string>
     <string name="account_proxy_field">Proxy</string>