Move implementations of Framework struct functions out of master.hpp

[Isabel Jimenez <co...@gmail.com>]

Hello everyone,

As part of an effort in reducing tech-debt and tickets that have been
stalling for some time, I'm working on
https://issues.apache.org/jira/browse/MESOS-2633.
As you can read in the ticket the discussion was summarize in this comment:
"... how about we create a master/framework.hpp (and master/slave.hpp
later), much like we did for master/metrics.hpp? Having definitions in
master.hpp that are defined in framework.cpp is a bit unintuitive (I've
seen a number of people get confused about this approach in
master/http.cpp).

Note that originally a master/metrics.cpp file was added on the assumption
that it would speed up build times, which likely didn't hold. Since you
didn't find a compile time decrease from the current approach, I'd suggest
just keeping all the code together in a master/framework.hpp header. Note
also that this lets you forward declare 'Framework"

Any additional thoughts before we move forward?

Isabel