[2.3] Manager Theme: Superboxselect Fix for Safari

The issue was reported here: http://forums.modx.com/thread/92604/listbox-multi-select-tv-values-not-visible-in-manager-when-selected-in-safari

The problem was, that the code that powers the superboxselect for some reason (probably older safari versions) made the close button element a "button" instead of an "a" element which caused the following UI glitch:

![bildschirmfoto 2014-08-09 um 14 54 00](https://cloud.githubusercontent.com/assets/445501/3866170/1f76032e-1fc5-11e4-8bc9-5ad5bff671aa.png)

As the source code for the superboxselect is found compressed in manager/assets/modext/util/utilities.js I replaced the compressed code with the uncompressed sourcecode of that plugin to fix the issue (and probably more to come for IE11)

After the fix it looks and works as it should:

![bildschirmfoto 2014-08-09 um 14 55 17](https://cloud.githubusercontent.com/assets/445501/3866173/6216a53a-1fc5-11e4-8dff-7af39f9bf7e4.png)

the issue is, that Safari has this "feature" of not making anchor elements focusable via tabs by default: http://stackoverflow.com/questions/8747689/safari-tabbing-focus-doesnt-work-in-5-1-2 so if a user wants that it has to be enabled in safaris settings. I think this shouldn't be forced by the code (and thus make problems in other areas like UI) but rather left to the safari users themselves, but this is a topic of discussion (it would probably also be possible to just adjust the css styles for that specific button element)...

![bildschirmfoto 2014-08-09 um 15 09 09](https://cloud.githubusercontent.com/assets/445501/3866195/c61a047c-1fc6-11e4-833b-69e5e1ef2a1b.png)