Docs and notion of active packages

[mschauer]

I wanted to give feedback on some hidden assumptions and things unclear to me which might help in writing the docs.

• Does activate "do" something or does it only change a status? Does this status only affect LOAD_PATH and Pkg?
• Does activate have any permanent or global effects, or only affect the current Julia process.
• Activate's docstring mentions a home project environment but that is not in the glossary. There is also a circularity here I do not understand: Quoting "If no argument is given to activate, activate the home project, which is the one specified by either --project command line when starting julia, or JULIA_PROJECT environment variable." What if no project-command is given and no JULIA_PROJECT is defined which is the standard? Similar issue with "The depot path is controlled by the Julia DEPOT_PATH global variable which is populated at startup based on the value of the JULIA_DEPOT_PATH environment variable" This seems to have a default ~/.julia?
• " The active environment is the environment that is
  modified by executing package commands." Confusing, does not apply to generate for example.
• The apparent difference between current and active project is too subtile, a warning should be added.

[KristofferC]

Issue moved to JuliaLang/Pkg.jl #746 via ZenHub

[mschauer]

Thank you.