Added TYPO3 12.4 LTS support

Tnx @joey-beech-it

TYPO3 11 support

2.0.1

[TASK] Raise version to 2.0.1

TYPO3 10 LTS compatibility release

[TASK] Add support TYPO3 10.4 LTS (#12)

Since the extension is actually feature-complete we decided to remove
support for TYPO3 < 10.

- delete removed ext_emconf.php settings and raise TYPO3 core
  version constraint
- remove TYPO3_MODE check in ext_localconf.php
- composer.json: use new spelling for used license
- composer.json: raise TYPO3 core version constraint
- composer.json: remove superfluous replace.gravatar option
- composer.json: add extra.typo3/cms.extension-key option
- use new ExtensionConfiguration class to retrieve extConf
- use PHP return type declarations
- ProxyController: use Request/Response
- ProxyController: remove bundled guzzle client logic
- remove bundled guzzle since it is shipped with TYPO3 core
- GravatarProvider: add missing default setting for useProxy
- README: add info about versions
- a11y: remove title attribute in extension icon

Resolves: #11

TYPO3 9LTS composer compatibility release

1.0.2

[TASK] Raise version to 1.0.2

1.0.1

TYPO3 8LTS bugfix release

Release 1.0.0

New release with the proxy feature provided by @rvock and some small bugfixes. Now marked as compatible with TYPO3 8 LTS.

TYPO3 8.0 compatibility release

0.0.7

[TASK] Set fallback to retro