i18n: Update transifex configuration file

transifex.net has changed domain to transifex.com.
i18n: Update translations

Updated translations:

- de_DE (German -- incomplete)
- et (Estonian -- incomplete)
- fr (French)
- ru (Russian)
- zh_CN (Chinese)

New translations:

- el (Greek)
- fa (Persian)
- id (Indonesian)
- pt_PT (Portuguese -- incomplete)