Add 'gcn!' for the '--no-edit' option. (#4830)

Remove the '-s' option from 'gcan!'
Add 'gcans!'. It is the same as the current 'gcan! -s'.

plugins/git/git.plugin.zsh

@@ -58,9 +58,11 @@ alias gbss='git bisect start'
 
 alias gc='git commit -v'
 alias gc!='git commit -v --amend'
+alias gcn!='git commit -v --no-edit --amend'
 alias gca='git commit -v -a'
 alias gca!='git commit -v -a --amend'
-alias gcan!='git commit -v -a -s --no-edit --amend'
+alias gcan!='git commit -v -a --no-edit --amend'
+alias gcans!='git commit -v -a -s --no-edit --amend'
 alias gcam='git commit -a -m'
 alias gcb='git checkout -b'
 alias gcf='git config --list'