Documentation requirements for LogBack (default logger)

[mrutkows]

With the noted library use in LICENSE of "logback: which uses LGPL, have we done enough? After reading the advice in URL below, we address #2, but can we address #1?

https://softwareengineering.stackexchange.com/questions/86142/what-exactly-do-i-need-to-do-if-i-use-a-lgpl-licenced-library/86158

as noted logback is default logger as per docs:
https://github.com/apache/incubator-openwhisk/blob/925500cf8d34bb75bebd077ea057af236eba0b01/docs/logging.md

Default Logging Provider

OpenWhisk uses Logback as default logging provider via slf4j.

Logback can be configured in the configuration file logback.xml.

Besides other things this configuration file defines the default log level for OpenWhisk. Akka Logging inherits the log level defined here.

If we can show another logger over the same Interface this could satisfy #1

[houshengbo]

I found out a nice video, giving instructions regarding how to create the LICENSE for a project:
https://vimeo.com/171210141

When the project needs to depend on another project with dual license, we can pick up one of the licenses, which is more friendly to our need.

LogBack is under two licenses: Eclipse 1.0 and GNU LPGL 2.1, so we can select Eclipse 1.0 as a friendly choice for open source project.

[houshengbo]

Revisit this issue for further binary releases.