controlpanel.cpp: Increases general verbosity of command results.
controlpanel.cpp: Standardize error wordings

When a network cannot be found for a user, and where a command will output an error under such circumstances, use similar wording in each message.
controlpanel.cpp: Fixed a Fail to Compile error introduced in prior commit.
Merge commit 'refs/pull/295/head' of github.com:znc/znc