* oauth2 (oauth2-authz-bearer-header): Change arg name.

* oauth2 (oauth2--created-at): Use if-let.

* oauth2 (oauth2-auth-and-store): Remove comment.

* oauth2 (oauth2--created-at): New function.

* oauth2 (oauth2--epoch-time): New function.

* oauth2: Use rx with string-match-p.

* oauth2 (oauth2-extra-headers): Update doc string.

* oauth2: Remove oauth2--url-http-handle-authentication-hack

(oauth2-auth-and-store): Check the token expiration date.
(oauth2-token): Add new slots.

Add LICENSE and Eldev.

* oauth2: (oauth2-token): Fix formatting.

* oauth2: Update version to 0.17

* oauth2: Update version to 0.17, require Emacs version 27.1.
(oauth2-request-authorization, oauth2-request-access): use cl-defun,
update doc string.
(oauth2-token): make read-only.
(oauth2-request-access): update accordingly to changes
(oauth2-auth, oauth2-compute-id, oauth2-url-append-access-token): Update doc string.
(oauth2-auth-and-store): change order of args and update doc string.
(oauth2--url-advice): Rename.

fix: add missing oauth2 group for custom variables

* .gitignore: New file

* packages/oauth2/oauth2.el: update version to 0.15

* packages/oauth2/oauth2.el: Use lexical-binding, cl-lib, and nadvice

(oauth2-token-file): Remove :group arg for non-existing group.
(oauth2--url-http-handle-authentication-hack): New function
extracted from the previous defadvice.
(url-http-handle-authentication): Use it.

feat(oauth2): do not include &client_secret if no client_secret set

Some providers do not like having client_secret passed when it is empty.

Thanks Andrew Cohen <acohen@ust.hk>

fix(oauth2): rename forgotten instance of resource-url -> scope

This is version 0.13

Thanks Rainer Gemulla <rgemulla@uni-mannheim.de>

feat(oauth2): add state parameter support, rename resource-url to scope

The resource-url is actually a scope.
Add support for optional state parameter.

This is version 0.12.

Thanks Xu Chunyang <xuchunyang56@gmail.com>

Fix some quoting problems in doc strings

Most of these are minor issues involving, e.g., quoting `like this'
instead of 'like this'.  A few involve escaping ` and ' with a
preceding \= when the characters should not be turned into curved single
quotes.

oauth2: send authentication token via Authorization header