* bug145-ProvideHelp:
Use "${docdir}/Commands.txt" as help text file
Add a note that "help file" is updated on startup and REHASH only
Add doc/Commands.txt which should document all commands
Implement Help() function parsing and returning the help text
Document "HelpFile" in sample-ngircd.conf and ngircd.conf.5
Implement new configuration option "HelpFile"
IRC_HELP(): Code cleanup
Refactor Read_Motd() into Read_TextFile()