Fix memory leaks in the way pcre is used.
Remove additional string copy from QByteArray.

Don't leak the string that defines the regex and since QByteArray's are
null terminated and contiguous in memory, we don't need to copy them.
Make mpConsole in Host into a QPointer.

QPointer is set to null when the thing it points to is deleted.
Don't access mpConsole if it is null.