- Cleaned up UID introduction / NICK change related code


git-svn-id: svn://svn.ircd-hybrid.org/svnroot/ircd-hybrid/branches/8.2.x@4091 82007160-df01-0410-b94d-b575c5fd34c7
- m_nick.c: improve documentation


git-svn-id: svn://svn.ircd-hybrid.org/svnroot/ircd-hybrid/branches/8.2.x@4092 82007160-df01-0410-b94d-b575c5fd34c7