Update WP changelog for removed and renamed options

src/plugins/wp/Changelog

@@ -26,7 +26,15 @@ Plugin WP 20.0 (Calcium)
 
 - TIP         [2019/09/17] Using all selected Why-3 provers for proof search
 - Gui         [2019/09/17] Updated panel for provers, models, cache, etc.
+- WP          [2019/09/16] Removed option -wp-include
+- WP          [2019/09/16] Removed option -wp-why3
+- WP          [2019/09/16] Removed option -wp-why-lib
+- WP          [2019/09/16] Removed option -wp-depth
+- WP          [2019/09/16] -wp-why-opt renamed -wp-why3-opt
 - WP          [2019/09/12] New cache mechanism for why3 provers, see -wp-cache option
+- WP          [2019/09/11] -wp-extensional now defaults to true
+- WP          [2019/09/11] -wp-init-const now defaults to true
+- WP          [2019/09/11] -wp-init-alias renamed -wp-alias-init
 -! WP         [2019/09/17] Deprecated native alt-ergo & coq output, see -wp-prover option
 -! WP         [2019/07/05] -wp-prover <p> now defaults to <why3:p> (including default alt-ergo)
 -! WP         [2019/07/05] Use native Why3 API (now requires why3 at compile time)