Don't allow a linker to link a WBE to (another) WBE.
Don't allow linking a WBE to itself.
Fixes #246
Merge pull request #243 from Micky2506/no-link-wbe

Don't allow a linker to link a WBE to (another) WBE.
Remove duplicate chat message sending.
Merge pull request #247 from Micky2506/chat-helper

Remove duplicate chat message sending.