Feedback for log4erl

Hi,

I've just seen some comments to say about a couple of emails I received from log4erl users. The first was from Loren of StackHub requesting XML appneder and the other from Kuba submitting an update to have log4erl handle calls to error_logger and requesting a fix to file_appender.

The bug in file_appender is that it copies files during rotation instead of just renaming them. For large files, this could results in timeouts or even crashes the program. I don't know what was I thinking but it's need a fix.

XML appender should be available in the next release and I'll also include Kuba's code and a fix to file_appender along. Thanks to Loren and Kuba for the feedback. Keep your suggestions coming and good luck.

Ahmed