Added an administration setting to allow issue start date to be defaulted to blank (nil) at issue creation (#2269).

Based on the patch of #2277 contributed by Mischa The Evil.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@7733 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/views/settings/_issues.html.erb

@@ -5,6 +5,8 @@
 
 <p><%= setting_check_box :issue_group_assignment %></p>
 
+<p><%= setting_check_box :default_issue_start_date_to_creation_date %></p>
+
 <p><%= setting_check_box :display_subprojects_issues %></p>
 
 <p><%= setting_select :issue_done_ratio, Issue::DONE_RATIO_OPTIONS.collect {|i| [l("setting_issue_done_ratio_#{i}"), i]} %></p>