Merge pull request #2001 from LCHeather/patch-1

Removed dead link, edited externals SDK text

Author: livecodepanos

Documentation/guides/Extending LiveCode.md

@@ -2288,15 +2288,12 @@ player object, and more.
 
 ### The Externals SDK
 
-We provide a developer kit for writing externals which includes 
-documentation and examples. You may download this kit from:
+Occasionally LiveCode Builder may not be what you need to create your extension. We provide a legacy developer kit for writing externals in C++ which includes documentation and examples. 
 
-<http://downloads.runrev.com/resources/externals/revexternalssdk.zip>
-
-The following newsletter articles will also help you get started:
+The following newsletter articles will help you get started:
 
 * [External Writing for the Uninitiated – Part 1](http://newsletters.livecode.com/november/issue13/newsletter5.php)
 
 * [External Writing for the Uninitiated – Part 2](http://newsletters.livecode.com/november/issue14/newsletter3.php)
 
-* [Writing Externals for Linux with 2.9 or later](http://newsletters.livecode.com/october/issue34/newsletter1.php)
+* [Writing Externals for Linux with 2.9 or later](http://newsletters.livecode.com/october/issue34/newsletter1.php)