Update ChangeLog

@zdenko Please change as you see fit.

My confusion is because, https://github.com/tesseract-ocr/tesseract/releases shows
on Nov 8, 2016 
4.00.00alpha  …
 c1c1e42   zip   tar.gz

If someone gets that zip/tar, it will not have all the items listed on Changelog for 4.0.0-alpha.

ChangeLog

@@ -1,4 +1,7 @@
-2017-03-24 - V4.00.00-alpha-cf245f8  
+2017-03-24 - V4.00.00-alpha
+  * Added new neural network system based on LSTMs, with major accuracy gains.
+  * Improvements to PDF rendering.
+  * Fixes to trainingdata rendering.  
   * Added LSTM models+lang models to 101 languages. (tessdata repository)
   * Improved multi-page TIFF handling.
   * Fixed damage to binary images when processing PDFs.
@@ -38,11 +41,6 @@
   * Added option to build Tesseract with CMake build system.
   * Implemented CPPAN support for easy Windows building.
 
-2016-11-11 - V4.00.00-alpha
-    * Added new neural network system based on LSTMs, with major accuracy gains.
-    * Improvements to PDF rendering.
-    * Fixes to trainingdata rendering.  
-
 2016-02-17 - V3.04.01
   * Added OSD renderer for psm 0. Works for single page and multi-page images.
   * Improve tesstrain.sh script.