Datepicker inline "onclick" handler causes CSP violations

[dmethvin]

Datepicker injects some HTML into the page using $() that has an inline JavaScript onclick handler. In environments that support Content Security Policy or other script injection measures, this causes a security exception. Datepicker throws an exception when initialized in a Windows 8 Metro environment, for example. This appears to be the only UI widget using inline handlers.

​https://github.com/jquery/jquery-ui/blob/1.8.20/ui/jquery.ui.datepicker.js#L1447

​https://dvcs.w3.org/hg/content-security-policy/raw-file/tip/csp-specification.dev.html#script-src

​https://wiki.mozilla.org/Security/CSP/Specification#No_inline_scripts_will_execute

​http://msdn.microsoft.com/en-us/library/windows/apps/hh849625.aspx

[Scott González]

Duplicate of #3945.