24h time format and date settings

[slavko989]

Half of the world use the 24 hour format, so it would be nice to make it available as an option in the client app.
And also, concerning the date format, some countries prefer the day written first and the month second (or Jan/Feb/Mar format).
It would be wise to just read the system settings, and then use the same format in Idena client as the system does.