Impove opera blank drag image workaround (stolen from codemirror)
Fix issue with blinking cursor on drag over

This happens when dragging from another app. Editor can get focused on app icon hovering (on a Windows taskbar).
highlight option tags as form elements
Added VHDL syntax highlighting, and example code. issue #1642
Revert "Added VHDL syntax highlighting, and example code. issue #1642"

This reverts commit 56a37a4053b8ace63eb4d113cb66157a7374b232.
Added VHDL syntax highlighting, and example code. issue #1642
Update vhdl.js

Added license block
Update vhdl_highlight_rules.js

Added license block
Merge pull request #1653 from adamjimenez/patch-19

highlight option tags as form elements
Merge pull request #1654 from asm2750/add-vhdl-syntax

Add vhdl syntax
[IME] pressing enter on ie reverts last input
use `text-indent: -1em;` to hide cursor on ie

as suggested in https://github.com/ajaxorg/ace/issues/1640
restore textInput.setReadOnly call

needed for disabling contextmenu items
fix spellcheck extension on chrome
fix #1650 Editor looses focus on scrollbar click in the Google Chrome
Merge pull request #1658 from ajaxorg/bugfix/textinput

Bugfix/textinput
multiline strings throw out error line numbers

e.g:

```
<?php
$foo = "test
multiline

string"
a
?>
```
shows  error on line 3 instead of 6.
remove unnecessary new line repace
Change mouse capture target container -> content

To prevent hover activity of scrollbars in Firefox
Merge pull request #1661 from danyaPostfactum/dnd-fixes

Some drag'n'drop fixes