Delete the old broken test suite.•••This doesn't work properly and is disabled in both debug & release
builds. It will be resurrected with a proper unit testing framework
in the future.
Add the reason to xline removal notices. (#1545)•••Show the reason in manual xline removal SNOTICEs, just like
expiry SNOTICEs do.
This modifies XLineManager::DelLine() to require another string
reference passed to it.
Requested by @Robby-.