Regen INSTALL after Win32 sdl2 drop; also ja_JP magic docs

docs/ja_JP.UTF-8/html/INSTALL.html

@@ -93,12 +93,12 @@
             Installation Documentation          </h1>
 
           <p>
-            Copyright &copy; 2002-2022 by various contributors; <a href="../../AUTHORS.txt">AUTHORS.txt</a> 参照.<br>
+            Copyright &copy; 2002-2023 by various contributors; <a href="../../AUTHORS.txt">AUTHORS.txt</a> 参照.<br>
             <a href="https://tuxpaint.org/">https://tuxpaint.org/</a>
           </p>
 
           <p>
-            2022年9月23日          </p>
+            2023年3月23日          </p>
         </center>
       </header>
 
@@ -636,8 +636,8 @@
                     <li>
                       Expand the tar-ball and change the directory name so that the final packaging process can find related files.                      <blockquote>
                         <code>
-                          $ tar zxvf tuxpaint-A.B.C-sdl2.tar.gz<br/>
-                          $ mv tuxpaint-A.B.C-sdl2 tuxpaint-sdl2<br/>
+                          $ tar zxvf tuxpaint-A.B.C.tar.gz<br/>
+                          $ mv tuxpaint-A.B.C tuxpaint<br/>
                         </code>
                       </blockquote>
                     </li>
@@ -648,7 +648,7 @@
                     <li>
                       Fetch the developing source tree from git repository:                      <blockquote>
                         <code>
-                          $ git clone -b sdl2.0 https://git.code.sf.net/p/tuxpaint/tuxpaint tuxpaint-sdl2
+                          $ git clone https://git.code.sf.net/p/tuxpaint/tuxpaint tuxpaint
                         </code>
                       </blockquote>
                     </li>
@@ -659,7 +659,7 @@
             <p>
               Now you can build Tux Paint as follows:              <blockquote>
                 <code>
-                  $ cd tuxpaint-sdl2<br/>
+                  $ cd tuxpaint<br/>
                   $ make bdist-win32<br/>
                 </code>
               </blockquote>
@@ -683,7 +683,7 @@
           <p>
             Before building an installer, edit the "<code>tuxpaint.iss</code>" file and enable one of the lines starting with "<code>#define BuildTarget=</code>", depending on the architecture of the installer you want to create.          </p>
           <p>
-            Then, you can easily build an executable installer by right-clicking on the "<code>tuxpaint.iss</code>" icon in the "<code>win32</code>" directory and selecting "Compile" on the list.  It will run for a while, and eventually you will find a "<code>tuxpaint-<i>X.Y.Z</i>-windows-sdl2.0-&lt;arch&gt;-installer.exe</code>" file in the same directory.          </p>
+            Then, you can easily build an executable installer by right-clicking on the "<code>tuxpaint.iss</code>" icon in the "<code>win32</code>" directory and selecting "Compile" on the list.  It will run for a while, and eventually you will find a "<code>tuxpaint-<i>X.Y.Z</i>-windows-&lt;arch&gt;-installer.exe</code>" file in the same directory.          </p>
         </section><!-- H3: Building the Tux Paint Windows Installer -->
 
         <section class="indent"><!-- H3: Running the Tux Paint Windows Installer -->

docs/ja_JP.UTF-8/html/README.html

@@ -232,7 +232,7 @@
     <a href="#using_tools_drawing_fill">「ぬる」ツール</a>に、領域の輪郭に合わせてグラデーションをつけるモードが追加されました。  </dd>
 
   <dt>15個の新たな<strong>「まほう」</strong>ツールの追加  <dd>
-    「めいろ」, 「めだま」, 「けがわ」, 「えんけい」, 「ほうしゃ」, 「りったいメガネ」, 「いろぶんかい」, Double Vision, 「ほうわ」, 「ひほうわ」, 「だっしょく」, 「いろのこし」, 「まんげきょう4」, 「まんげきょう6」, 「まんげきょう8」, 「かがやき」  </dd>
+    「めいろ」, 「めだま」, 「けがわ」, 「えんけい」, 「ほうしゃ」, 「りったいメガネ」, 「いろぶんかい」, 「ふくし」, 「ほうわ」, 「ひほうわ」, 「だっしょく」, 「いろのこし」, 「まんげきょう4」, 「まんげきょう6」, 「まんげきょう8」, 「かがやき」  </dd>
 
   <dt><strong>けしゴム</strong> のショートカット</dt>
   <dd>