Reviewed by Tim.

        - <rdar://problem/5792587> AJAX (XMLHttpRequest) support for the Inspector (17776)
        - Add XMLHttpRequest support to the inspector.

        * English.lproj/InspectorLocalizedStrings.js: Specify capitalization
        instead of using text-transform because XHR must capitalize all the letters.
        * page/inspector/Resource.js: Assume XHRs are textType even though this
        may not always be true.
        Also add the XHR category and let all mime types be consistent with it.
        * page/inspector/ResourcesPanel.js: Set the XHR category color.
        * page/inspector/inspector.css: Make XHRs yellow and fonts red because
        XHRs are more common than fonts and yellow next to orange (scripts) is
        not as harsh on the eyes as red next to orange.
        * page/inspector/inspector.js: Specify capitalization again.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@31922 268f45cc-cd09-0410-ab3c-d52691b4dbfc