#4 async appenders

[matt baldree]

Here are the asynchronous appenders I wrote to use
with log4net. I included a sequence diagram to show the
basic doAppend() flow. For the most part, I
kept the design already in place for FileAppender and
RollingFileAppender. The difference is that I do not use
TextWriters to write characters but FileStreams to write
encoded bytes. Any feedback would be great.

[matt baldree]

async appenders