Prepare for v1.1.0 release

[Xymph]

Release summary:

This release adds a new undelete method, supports the API's deletetalk parameter in the delete methods based on a new mechanism to handle version-dependent parameters of API modules, updates the dependency on rmccue/requests to v2.x, resolves several warnings, and improves code formatting and commenting. For more details on these changes, including links to the corresponding pull requests, please check the Changelog.

[Xymph]

Obviously #155 needs to be merged first, but I don't know whether that will affect merge-ability of Changelog.md here. And if so, how to resolve that, so please advise.

Also, the release date needs to be updated in two places before the actual merge of this PR.

[waldyrious]

Obviously #155 needs to be merged first, but I don't know whether that will affect merge-ability of Changelog.md here. And if so, how to resolve that, so please advise.

The edits from both PRs touch different lines of the file, so git is able merge them to without conflicts. I'll go ahead and rebase this branch, edit the release date and merge the PR :)

[waldyrious]

After merging the PR, I have performed the steps described in GOVERNANCE.md:

• Published the new git tag and release. I used the text from the opening comment above for the release, but edited it lightly and formatted it as a list to it easier to read.
• Updated Packagist and MediaWiki.org's PHP libraries table.
  • I also made some edits to Wikipedia's PHP bot frameworks table, though not directly related to this release (those edits triggered further updates to the table; see in particular those discussed in #158)

As a follow-up to having gone through this process, I created #157 to make the release instructions slightly clearer and more comprehensive; in particular, that added the recommendation to leave a comment like this, to keep an explicit record of the release steps taken.