Use Marker as Android tag

[ppkarwasz]

Currently log4j2-android uses the last fragment of a logger's name (e.g. MyActivity if the logger's name is foo.bar.MyActivity) as Android Log tag.

As far as I understand Android Log tags fulfill the same function as Log4j API markers. You might want to consider using those as tags, with a reasonable default (LOG4J?) if the marker is not provided.

Markers are also supported by at least SLF4J and the log4j-slf4j-impl/log4j-slf4j2-impl bridges translate them to Log4j API markers. I recently modified commons-logging (which does not support markers) to use a single COMMONS-LOGGING marker (see Log4jApiLogFactory.