Disallow # in keys.
Disallow # in keys.

We're now back to only failing the two tests related to string escaping and
unicode in the toml-test suite.

Nephatrine/cpptoml,Nephatrine/cpptoml,skystrife/cpptoml,skystrife/cpptoml,Payshares/cpptoml,vadz/cpptoml,zzzworm/cpptoml,Payshare/cpptoml,vadz/cpptoml