Added transifex script from Leo Feyer
Improved transifex tool and added config file
Deleted all languages except english
CS
Removed tl_content, the core is not using it

We'll keep the basic ContentElement, so developers should use it.
We can then still extend it's functionality.
Dropped a language file without useful content
Improved language files
Moved Paypal labels to tl_iso_payment_modules language file
Authorize.Net now has its own language file
Finished cleaning the language files
Use TL_LANG for error messages
Use $GLOBALS['TL_LANG']['MSC'] instead of $GLOBALS['TL_LANG']['ISO']
Use $GLOBALS['TL_LANG']['MSC'] instead of $GLOBALS['ISO_LANG']['MSC']
Use TL_LANG instead of ISO_LANG
Improved language files of other core modules
Updated transifex tool to include the Isotope copyright
Updated transifex configuration
Merge branch 'feature/transifex' into develop