Update themes/default/views/main/main_js.php

* fix issue with incorrectly formatted timeline dates
* prevented timeline from displaying on safari and on most mobile devices (tablets/phones)
* closes #951
Moving media elements in xml download file to the bottom as opposed to being first, and removing field default notice that ends up getting repeated for each radio button option #792
Adding documentation/guides on reports upload via CSV/XML from the Ushahidi wiki #792
Add phpdoc for application/helpers/download.php

Ref request from @aoduor on ec63cf8
Merge pull request #953 from dkobia/develop

Update themes/default/views/main/main_js.php