Changes

* Charts appear without content - solution related to a security vulnerability update to Browsers. (i.e. local HTML files ought not to be authorized to open files from different sub-directories) This shouldn't be a problem once the files are uploaded to a server. It is just local mode that is affected. Workarounds for local mode available for:** set [https://gramps.discourse.group/t/web-page-reports-have-no-content/411/8 Firefox]<tt>privacy.file_unique_origin flag</tt> to false in [http://kb.mozillazine.org/About:config about:config]** Chrome launch flags: <pre>C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --allow-file-access-from-files --allow-file-access --allow-cross-origin-auth-prompt</pre>