Factor out HTTPAdapter.proxy_manager_for for #2048
update AUTHORS.rst
improve `proxy_manager_for` re-usability by subclass
allow pool_kwargs to be specified in init_poolmanager
indentation change for code review
handle 308 redirection the same as 301 and 302
rename resume/resume_incomplete to permanent_redirect according to rfc7238

Use temporary_redirect intead of temporary_moved to make the words
line up nicely ;-)
Re-add resume to not break existing apps
as requested by Cory Benfield
Merge pull request #2090 from ericfrederich/fix_308

handle 308 redirection the same as 301 and 302
don't make duplicate requests for permanent redirects
Merge branch 'master' into redirect_cache
Merge pull request #2095 from ericfrederich/redirect_cache

Redirect cache
Update out-there.rst

Remove french blog post which is now a deadlink.
Merge pull request #2097 from bkerensa/patch-1

Update out-there.rst
Merge pull request #2049 from codedstructure/adapter-proxy_manager_for

Separated out proxy_manager_for to fix #2048
Update quickstart.rst

line 394: correct an input error.
Merge pull request #2112 from np-csu/patch-1

Update quickstart.rst
Update how we check verify when inspecting env variables
Replace dead link with StackOverflow answer
Merge pull request #2116 from sigmavirus24/fix-2107

Replace dead link with StackOverflow answer