QmlJS: Split Context and ScopeChain.

Context is created by Link and has information about imports
for all Documents in a Snapshot.

ScopeChain represents how lookup is done at a specific place in
a Document.

Change-Id: I874102d57bbaf1a497fa3f27633bed6ee75dcf10
Reviewed-on: http://codereview.qt.nokia.com/1694
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@nokia.com>

src/libs/qmljs/qmljs-lib.pri

@@ -30,7 +30,8 @@ HEADERS += \
     $$PWD/qmljstypedescriptionreader.h \
     $$PWD/qmljsscopeastpath.h \
     $$PWD/qmljsvalueowner.h \
-    $$PWD/qmljscontext.h
+    $$PWD/qmljscontext.h \
+    $$PWD/qmljsscopechain.h
 
 SOURCES += \
     $$PWD/qmljsbind.cpp \
@@ -52,7 +53,8 @@ SOURCES += \
     $$PWD/qmljstypedescriptionreader.cpp \
     $$PWD/qmljsscopeastpath.cpp \
     $$PWD/qmljsvalueowner.cpp \
-    $$PWD/qmljscontext.cpp
+    $$PWD/qmljscontext.cpp \
+    $$PWD/qmljsscopechain.cpp
 
 RESOURCES += \
     $$PWD/qmljs.qrc