Added dump-leveldb script (#170)

.gitignore

@@ -23,7 +23,7 @@ core
 *.stackdump
 /*_history
 tags
-/webstore*.zip
+*.zip
 foo.*
 
 # Output directories

tools/dump-leveldb.js

@@ -0,0 +1,33 @@
+// dump-leveldb.js: Dump the data from a Chrome/Vivaldi
+// Extension Settings database.
+//
+// See https://github.com/cxw42/TabFern/issues/170#issuecomment-473280320
+// for usage instructions.
+//
+// Prerequisites:
+//      npm install levelup leveldown
+//
+// This code by cxw42 2019, CC-BY-SA 3.0.  Thanks to the sample at
+// https://github.com/Level/levelup/blob/master/README.md and to
+// https://superuser.com/a/1088579/269989 by
+// https://superuser.com/users/219095/daniel-b
+
+var levelup = require('levelup')
+var leveldown = require('leveldown')
+
+// 1) Create our store
+var db = levelup(leveldown('./data'))
+
+db.createReadStream()
+  .on('data', function (data) {
+    console.log(data.key.toString('utf8'), '=', data.value.toString('utf8'))
+  })
+  .on('error', function (err) {
+    console.log('Oh my!', err)
+  })
+  .on('close', function () {
+    console.log('Stream closed')
+  })
+  .on('end', function () {
+    console.log('Stream ended')
+  });