viewport meta tag is using the attribute 'property' instead of 'name' 

Possible Fix #405 - viewport meta tag is using the attribute 'property' instead of 'name' which is preventing the e107 bootstrap responsive theme behave adaptively with screen width, when testing with actual mobile device. (Used an android device with 480x800 px resolution). Replacing the 'property' attribute with 'name' attribute fixes the issue. Screenshots attached before and after applying this change. The meta tag attribute name of 'property' is used in OG meta protocol only I believe.

Ref links to developer notes on meta viewport for some major browsers:
https://developer.mozilla.org/en-US/docs/Mozilla/Mobile/Viewport_meta_tag
http://developer.apple.com/library/safari/#documentation/appleapplications/reference/SafariHTMLRef/Articles/MetaTags.html
http://dev.opera.com/articles/view/an-introduction-to-meta-viewport-and-viewport/

Screenshots:
before:
![screenshot_2013-07-05-23-47-35](https://f.cloud.github.com/assets/315195/755911/afd54a98-e5cd-11e2-8aba-46f587be1a20.png)
after:
![device-2013-07-06-001020](https://f.cloud.github.com/assets/315195/755912/bb7f254e-e5cd-11e2-91f5-374455d2d114.png)