Fix some failures with newer versions of clang.

Some CoreGraphics headers generate warnings under newer versions of clang. Since they're system headers the warnings would
usually be suppressed, but we're adding the frameworks to the non-system framework search path so they're no longer treated
as system headers. We address this by removing the system paths from FRAMEWORK_SEARCH_PATHS and using the -iframework compiler
flag in OTHER_CFLAGS to add the paths to the system framework search path. We have to set OTHER_CFLAGS at the target level
in order for it to coexist with the ASAN-related OTHER_CFLAGS that's set in DebugRelease.xcconfig.

Reviewed by Dan Bernstein.

Source/WebCore:

* Configurations/WebCore.xcconfig:

Source/WebKit/mac:

* Configurations/DebugRelease.xcconfig:
* Configurations/WebKit.xcconfig:

Source/WebKit2:

* Configurations/BaseTarget.xcconfig:
* Configurations/DebugRelease.xcconfig:

Tools:

* DumpRenderTree/mac/Configurations/Base.xcconfig:
* DumpRenderTree/mac/Configurations/BaseTarget.xcconfig: A new .xcconfig file that's included by all target-specific .xcconfig files.
* DumpRenderTree/mac/Configurations/DebugRelease.xcconfig:
* DumpRenderTree/mac/Configurations/DumpRenderTree.xcconfig:
* DumpRenderTree/mac/Configurations/ImageDiff.xcconfig:
* DumpRenderTree/mac/Configurations/TestNetscapePlugIn.xcconfig:
* WebKitTestRunner/Configurations/Base.xcconfig:
* WebKitTestRunner/Configurations/BaseTarget.xcconfig: A new .xcconfig file that's included by all target-specific .xcconfig files.
* WebKitTestRunner/Configurations/DebugRelease.xcconfig:
* WebKitTestRunner/Configurations/InjectedBundle.xcconfig:
* WebKitTestRunner/Configurations/WebKitTestRunner.xcconfig:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@156611 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Add first()/last() to ElementIteratorAdapters
https://bugs.webkit.org/show_bug.cgi?id=122067

Reviewed by Darin Adler.

Add a convenient way for getting the first and last element if it exists.
        
Use it in some places.

* accessibility/AccessibilityNodeObject.cpp:
(WebCore::AccessibilityNodeObject::canvasHasFallbackContent):
* css/CSSFontFaceSource.cpp:
(WebCore::CSSFontFaceSource::getFontData):
* dom/Document.cpp:
(WebCore::Document::childrenChanged):
(WebCore::Document::removeTitle):
* dom/ElementChildIterator.h:
(WebCore::::first):
(WebCore::::last):
* dom/ElementDescendantIterator.h:
(WebCore::::first):
(WebCore::::last):
* html/HTMLFieldSetElement.cpp:
(WebCore::HTMLFieldSetElement::legend):
* html/HTMLLegendElement.cpp:
(WebCore::HTMLLegendElement::associatedControl):
* html/HTMLMediaElement.cpp:
(WebCore::HTMLMediaElement::finishParsingChildren):
(WebCore::HTMLMediaElement::selectMediaResource):
* svg/SVGElement.cpp:
(WebCore::SVGElement::title):
* svg/SVGFontFaceElement.cpp:
(WebCore::SVGFontFaceElement::rebuildFontFace):
* svg/graphics/SVGImage.cpp:
(WebCore::SVGImage::hasSingleSecurityOrigin):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@156612 268f45cc-cd09-0410-ab3c-d52691b4dbfc