This beings an experiment with nominal typing using what the TS community
calls "branding". The lack of nominal types was one of my biggest
disappointments with TS, so this should really help to mitigate bugs
resulting from misappropriation of data.
* src/server/token/Token.ts: New file.
* src/server/token/TokenDao.ts: Use Token{Id,Namespace}.
* src/server/token/TokenQueryResult.ts: Likewise.
* src/types/misc.d.ts: Introduce NominalType and UnixTimestamp.
* test/server/token/TokenDaoTest.ts: Use nominal types.