[logback-user] DBNameResolver

[Roy Cronise]

Merritt:

DBAppenderBase isn't in the loop, but has the event id column
name(EVENT_ID) coded into it and doesn't use the DBNameResolver.  The
event id column name is needed when they create the prepared statement
in DBAppenderBase and the database supports getGeneratedKeys.  Maybe
adding an abstract "getEventIdCol" in DBAppenderBase and implementing
it in DBAppender(which has the DBNameResolver).

Roy