新增：封面嵌入、歌词下载；修复Bug

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "lx-music-desktop",
-  "version": "0.3.2",
+  "version": "0.4.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -6243,6 +6243,11 @@
         "resolve-dir": "^1.0.1"
       }
     },
+    "flac-metadata": {
+      "version": "0.1.1",
+      "resolved": "https://registry.npm.taobao.org/flac-metadata/download/flac-metadata-0.1.1.tgz",
+      "integrity": "sha1-wC+KBtJL1bad4rhVEsbkW9j5F2w="
+    },
     "flat-cache": {
       "version": "2.0.1",
       "resolved": "https://registry.npm.taobao.org/flat-cache/download/flat-cache-2.0.1.tgz",
@@ -7534,7 +7539,6 @@
       "version": "0.4.24",
       "resolved": "https://registry.npm.taobao.org/iconv-lite/download/iconv-lite-0.4.24.tgz",
       "integrity": "sha1-ICK0sl+93CHS9SSXSkdKr+czkIs=",
-      "dev": true,
       "requires": {
         "safer-buffer": ">= 2.1.2 < 3"
       }
@@ -9410,6 +9414,14 @@
       "integrity": "sha1-bBUsNFzhHFL0ZcKr2VfoY5zWdN8=",
       "dev": true
     },
+    "node-id3": {
+      "version": "0.1.11",
+      "resolved": "https://registry.npm.taobao.org/node-id3/download/node-id3-0.1.11.tgz",
+      "integrity": "sha1-ypuX8MVOQPsjRuUptKxMFaDPFio=",
+      "requires": {
+        "iconv-lite": "^0.4.15"
+      }
+    },
     "node-libs-browser": {
       "version": "2.2.1",
       "resolved": "https://registry.npm.taobao.org/node-libs-browser/download/node-libs-browser-2.2.1.tgz",