parse_editable: clarify output

extras and editable_options are two different things
Fix environment extras installation for sdist

use pkg_resources.Distribution.requires instead of
Requirements.requirements to have environment markers parsing for free
It also unifies a little the process for wheel and non-wheel installs

closes #2174
drop egg_info_lines

and use pkg_resources.Distribution instead
switch extra requirements log to debug
Merge pull request #2153 from xavfernandez/xfernandez/extras_fix

Fix extras_require and environment markers in sdist