add tool for translation statistics

[Aigrefin]

Hi,

This basic tool helps detect missing translations and gives warnings when a field seems to have been copy-pasted instead of translated. It also gives a warning when the english translations of the extension are different from the ones of the eng.xml file.

Usage :
cd tools
lua translations_status.lua

Example output :

-- missing lang files
alb
scc
jpn
ben
mal
vie
-- missing translation keys
rum mess_err_wrong_path
rum mess_err_cant_download_interface_translation
hun mess_err_wrong_path
hun mess_err_cant_download_interface_translation
eng mess_err_wrong_path
eng mess_err_cant_download_interface_translation
eng mess_err_conf_access
slo int_no_support_mess
slo int_os_password
slo int_os_username
-- translations equal to the english version
-- or xml english translation different from program english translation
rum int_config
rum int_ok
hun int_ok
baq int_searching_transl
baq int_search_transl
eng mess_err_wrong_path
eng mess_err_cant_download_interface_translation
eng mess_err_conf_access
eng int_help_mess
eng action_search
eng mess_not_load
eng int_no_support_mess
eng int_os_password
eng int_os_username
eng action_hash
slo int_ok