New core-extensions to allow Docker volumes for third-party extensions (#2837)

* New core-extensions to allow Docker volumes for third-party extensions

#Fix https://github.com/FreshRSS/FreshRSS/issues/2650
Split our extensions directory into two:
1) Core extensions shipped with FreshRSS in ./lib/core-extensions/
2) Third-party extensions modified by end-users in ./extensions/ which
can easily be mounted as a Docker volume

* Example of Docker Compose with extensions

* Back-compatibility + fix array merge bug

4 files changed, 1 insertions, 26 deletions

diff --git a/extensions/README.md b/extensions/README.md
index 62766d6f2..9833196b4 100644
--- a/extensions/README.md
+++ b/extensions/README.md
@@ -1,4 +1,4 @@
-# FreshRSS extensions
+# FreshRSS third-party extensions
 
 You may place custom extensions for FreshRSS in this directory.
 
diff --git a/extensions/Tumblr-GDPR/README.md b/extensions/Tumblr-GDPR/README.md
deleted file mode 100644
index fc5e4dd50..000000000
--- a/extensions/Tumblr-GDPR/README.md
+++ /dev/null
@@ -1,4 +0,0 @@
-# Tumblr-GDPR
-
-Needed for accessing [Tumblr](https://www.tumblr.com/) RSS feeds from the European Union:
-bypass the [GPDR](https://en.wikipedia.org/wiki/General_Data_Protection_Regulation) check, implying consent.
diff --git a/extensions/Tumblr-GDPR/extension.php b/extensions/Tumblr-GDPR/extension.php
deleted file mode 100644
index 83bdf2189..000000000
--- a/extensions/Tumblr-GDPR/extension.php
+++ /dev/null
@@ -1,13 +0,0 @@
-<?php
-
-class TumblrGdprExtension extends Minz_Extension {
-	public function init() {
-		$this->registerHook('simplepie_before_init', array('TumblrGdprExtension', 'curlHook'));
-	}
-
-	public static function curlHook($simplePie, $feed) {
-		if (preg_match('#^https?://[a-zA-Z_0-9-]+.tumblr.com/#i', $feed->url())) {
-			$simplePie->set_useragent(FRESHRSS_USERAGENT . ' like Baiduspider');
-		}
-	}
-}
diff --git a/extensions/Tumblr-GDPR/metadata.json b/extensions/Tumblr-GDPR/metadata.json
deleted file mode 100644
index b5c33787b..000000000
--- a/extensions/Tumblr-GDPR/metadata.json
+++ /dev/null
@@ -1,8 +0,0 @@
-{
-	"name": "Tumblr-GDPR",
-	"author": "Alkarex",
-	"description": "Bypass Tumblr’ GPDR check (implying consent) for the European Union",
-	"version": 1.0,
-	"entrypoint": "TumblrGdpr",
-	"type": "system"
-}