Changelog for 2.156

What's new in 2.156 (2018-12-17)

• User account creation by administrators did not show error messages when it failed. (regression in 2.129) (issue 52869)
• Fix java.lang.IllegalStateException that could occur in rare cases on Jenkins startup. (issue 55197, issue 55070)
• Attempt to prevent NoClassDefFoundError: javax/servlet/ServletException under some conditions on agents. (issue 26677)
• Update Remoting from 3.27 to 3.28 to fix some minor issues and enhance NO_PROXY options. (full changelog, issue 47977, issue 48778, issue 49987, issue 50730, issue 51108, issue 54005)
• Replace the Flash implementation of the "copy to clipboard" feature with the native JavaScript equivalent. (issue 54933)
• Developer: Login and signup pages redesigned in 2.129 now can receive style contributions (footer view for SimplePageDecorator) from multiple plugins. (issue 54325)