Re: unicode support (wofstream and codecvt)

[Curt Arnold]

Thanks for the patch.  There have been a couple of emails related to 
Unicode support in log4cxx over the past few weeks and I believe that 
to do it right will require more changes than just fixing one appender, 
however I will review your patch as part of that effort.

Currently, log4cxx has the following issues:
log4cxx/tchar.h provides definitions that conflict with those in 
Win32's tchar.h for W2A, T2A, TCHAR, etc.  Under some circumstances, 
TCHAR for log4cxx/tchar.h is wchar_t and Win32's tchar.h defines is as 
char.

The log4cxx/tchar.h has a limit on the size of conversion that can be 
done with W2A, etc which results in message truncation.

log4cxx supports only one character type at a given instance, where an 
application may have multiple DLL's some of which are Ascii dominant 
and others Unicode dominant.

FileAppender has no support for encoding specification.
The XML configuration file could use characters not supported in the 
current code page which are likely to cause problems in ASCII builds.

My current plan is to rework of log4cxx so that exposes char*, wchar_t* 
and possibly unsigned short* (UTF-16) for the logging methods, uses 
either wchar_t or unsigned short* for all internal string 
representations and avoids conflicting with Win32's tchar.h.