Update translations from Transifex

Newly added languages: Esperanto (eo), Lithuanian (lt), Romanian (ro) and
Serbian (sr)

Many thanks to:
 - cs: Vít Pelčák <vit@pelcak.org>
 - de: ToBeFree <tobias@freiwuppertal.de>
 - eo: cordata <tiffypet@yahoo.com>, <recoverybenk@gmail.com>
 - es: Adolfo Jayme Barrientos <fitoschido@gmail.com>, enjolras <yo@miguelrevilla.com>
 - fi: Larso <larso@gmx.com>, Lasse Liehu <lasse.liehu@gmail.com>
 - lt: Liudas Alisauskas <liudas@akmc.lt>
 - nb: sandsmark <sandsmark@samfundet.no>
 - ro: Sergiu Bivol <sergiu@ase.md>
 - ru: sfionov <fionov@gmail.com>
 - sr: Jovan Jojkić <jovanjojkic@gmail.com>
 - tr: Volkan Gezer <volkangezer@gmail.com>
 - tr: zeugma <sunder67@hotmail.com>
 - uk: Yuri Chornoivan <yurchor@ukr.net>