Fix issue #127

Resume:

* Make the "CACHE_TAG" string on strings.xml not translatable
* Create transifex configuration ( .tx/config ) to easy pull and push translations using Transifex client. Please see: 
http://support.transifex.com/customer/portal/articles/995605-installation 
http://support.transifex.com/customer/portal/articles/1000855-configuring-the-client - only ".transifexrc" section
http://support.transifex.com/customer/portal/articles/960804-overview#user-client-08-type
http://support.transifex.com/customer/portal/articles/996157-getting-translations
http://support.transifex.com/customer/portal/articles/996211-pushing-new-translations

* Update Readme to informing that all efforts for translation were moved to Transifex


After pulling translations using a Transifex client, for each translation, Transifex client automatically creates a folder containing the translation

The folder name will be defined according to the following syntax: 

```
TMessagesProj/src/main/res/values-<lang-code>/string.xml
```