edit NCURSES_NO_UTF8_ACS's comment, add changelog entry

CHANGELOG.md

 CHANGELOG
 =========
 
+* Setup dialogs did not appear correctly when connecting to SSH using Putty on Windows.
+
 v0.17b (March 1, 2016)
 ----------------------
 

setup/start.sh

@@ -24,8 +24,9 @@ export LC_ALL=en_US.UTF-8
 export LANG=en_US.UTF-8
 export LC_TYPE=en_US.UTF-8
 
-# Fix for putty Line Drawing characters to be shown correctly
+# Fix so line drawing characters are shown correctly in Putty on Windows. See #744.
 export NCURSES_NO_UTF8_ACS=1
+
 # Recall the last settings used if we're running this a second time.
 if [ -f /etc/mailinabox.conf ]; then
 	# Run any system migrations before proceeding. Since this is a second run,