/who does not show half-ops

[thommey]

#97 implements half-ops but does not adjust the /who code to show half-ops as % in the flags parameter.

The master branch also does not have that feature. It prevents clients that use /who to retrieve prefixes from seeing it.

I believe the change would need to be placed at https://github.com/DALnet/bahamut/blob/master/src/m_who.c#L801-L806

Unfortunately it seems '%' is already used as a /who flag related to invisible users, so I don't know if it's even easily possible to fix this.