tfm: Change coding style
Make clang the default compiler.
tfm: Change the way we get and list events.
tfm: Make age classes being strings.

With age classes being ints, you can't have the classes
Male, Female, Veteran, Junior Male etc.
tfm: Change event to eventgroups.

The eventgroup is a collection of events, containing one event
for each age group.
tfm: Throw if you try to add the same event group twice.