The comments within indra/test/test.cpp promise that --debug is, in fact, like
LOGTEST=DEBUG. Until now, that was a lie. LOGTEST=level displayed log output
on stderr as well as in testprogram.log, while --debug did not.

Add LLError::logToStderr() function, and make initForApplication() (i.e.
commonInit()) call that instead of instantiating RecordToStderr inline. Also
call it when test.cpp recognizes --debug switch.

Remove the mFileRecorder, mFixedBufferRecorder and mFileRecorderFileName
members from SettingsConfig. That tactic doesn't scale.

Instead, add findRecorder<RECORDER>() and removeRecorder<RECORDER>() template
functions to locate (or remove) a RecorderPtr to an object of the specified
subclass. Both are based on an underlying findRecorderPos<RECORDER>() template
function. Since we never expect to manage more than a handful of RecorderPtrs,
and since access to the deleted members is very much application setup rather
than any kind of ongoing access, a search loop suffices.

logToFile() uses removeRecorder<RecordToFile>() rather than removing
mFileRecorder (the only use of mFileRecorder).

logToFixedBuffer() uses removeRecorder<RecordToFixedBuffer>() rather than
removing mFixedBufferRecorder (the only use of mFixedBufferRecorder).

Make RecordToFile store the filename with which it was instantiated. Add a
getFilename() method to retrieve it. logFileName() is now based on
findRecorder<RecordToFile>() instead of mFileRecorderFileName (the only use of
mFileRecorderFileName).

Make RecordToStderr::mUseANSI a simple bool rather than a three-state enum,
and set it immediately on construction. Apparently the reason it was set
lazily was because it consults its own checkANSI() method, and of course
'this' doesn't acquire the leaf class type until the constructor has completed
successfully. But since nothing in checkANSI() depends on anything else in
RecordToStderr, making it static solves that problem.