UTF-8 support for html form textarea. Changed displaying of textarea.

UTF-8 support for html form textarea. Changed displaying of textarea.

Including double-width glyph support.

Note: textarea is now drawn with blank collumn at end of lines. It seems
that this is more intuitive for users. It behaves similar as textareas in
graphical interfaces. I hope it will hold your interest.

+----+         +----+         +----+
|aaA | [right] |aaa_| [right] |aaa |
|aaa |         |aaa |         |Aaa |
|bb  |         |bb  |         |bb  |
+----+         +----+         +----+
+----+         +----+         +----+
|Aaa |  [end]  |aaa_|   [c]   |aaa |
|aaa |         |aaa |         |Caa |
|bb  |         |bb  |         |abb |
+----+         +----+         +----+
A, _, C - cursor positions.
[right] - right arrow
[end]   - ACT_END (End button)
[c]     - Letter c.

Now this code:
<textarea rows="3" cols="3">aaaaaabb</textarea>
represents textarea with 3x3 positions for chars.

Before this texteare behaved some kind of weirdly. That code above was
rendered like this:
+----+
|aaaa|
|aabb|
|_   |
+----+