Arbitrary country names

[yurloc]

The program must not rely on the assumption that input file will contain country names exactly as they are defined in CountryCode. Arbitrary country names must be accepted.

• The corresponding country flag will be displayed automatically when a matching country definition is found (current state).
• When the country name is not recognized, a default flag image will be used (for example IYPT logo).
• User will be allowed to map custom country name to one of the existing built-in names to get the correct flag.
• Nice to have: add possibility to use user-provided flags.

[yurloc]

also it would be great to let us edit the names of countries, because
with some countries like UK, USA it might be helpful to switch to the
shorter version (instead of United Kingdom etc.)