1.Few changes in class-amp-post-template.php to take care of the archive debug errors
Reference: #1130 #966

2.Replaced the fastimage with fasterimage for PHP 5.4+ #1191
		changes made in amp/includes/lib/fastimage
						amp/includes/lib/fasterimage
						amp/includes/sanitizers/class-amp-img-sanitizer.php
						amp/includes/utils/class-amp-image-dimension-extract.php
						amp/includes/utils/class-amp-wp-utils.php

3. Redux: A small change in redux-core/framework.php at line number 2962. #1219						

4. Make sure we are passing the integer in the date function Ticekt no #1241
	changes made in includes/class-amp-post-template.php on line 174 and 175

5. Added a filter called ampforwp_allow_featured_image, so users can show or hide Featured image according to the usage. #1071

6. Two Filters added at line number 92 and 124 in amp/includes/embeds/class-amp-gallery-embed.php to add extra parameters for Gallery. 

7. amp-video script added in amp/includes/sanitizers/class-amp-video-sanitizer.php #991

8. allow-popups added on line number 10 in amp/includes/sanitizers/class-amp-iframe-sanitizer.php #1099

9 Changed placeholder image path from assets folder to image folder
amp\includes\class-amp-post-template.php, line no: 58, Issue no: 1310
'placeholder_image_url' => AMPFORWP_IMAGE_DIR. '/placeholder-icon.png'

10. Embed Handlers: Added support for Vimeo, SoundCloud, Pinterest, Dailymotion and PlayBuzz  
11.Fixes: Old slug redirect for AMP URLs
		  Handle issues with data uri images in CSS
		  Output CSS for feature image
		  Fix attribute when adding AMP Mustache
		  Various documentation updates
		  Coding Standards
Check #1033 for more details on 10 and 11

12. Argument specific filters added at line number 43 and 47 of class-amp-content.php
Reason: To extend the functionality of sidebars and Pagebuilder

13. Foo Gallery Support code added in class-amp-img-sanitizer.php in line no 35 #1424
14. Filter added in class-amp-dom-utils.php on line no 37 #1462
15. amp_vimeo_parse_url filter applied in class-amp-vimeo-embed.php in line no 108
16. ampforwp_end_point_controller added in amp-helper-functions on line no 15 #1561
17. folder name updated from amp to ampforwp to avoid conflict in class-amp-post-template.php on line no 440 #1742
18. 'amp_fetch_image_mode_type' filter added in class-amp-image-dimension-extractor.php #1833
19. Modifications in class-amp-img-sanitizer.php for Lightbox support #1892
20. Modification is class-amp-blacklist-sanitizer.php #1958