Clang: Add revision and completion management

Reparsing a document is expensive so we should avoid it by all means. In
this patch we prevent that the same document is send again. It isn't send
too in advance of a code completion if there was no changes before the
the completion position.

Change-Id: I0bb786ba1d4e7ce08611a518cb32f8cf8f4d0037
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/plugins/cpptools/cpptools.pro

@@ -64,7 +64,8 @@ HEADERS += \
     stringtable.h \
     symbolfinder.h \
     symbolsfindfilter.h \
-    typehierarchybuilder.h
+    typehierarchybuilder.h \
+    senddocumenttracker.h
 
 SOURCES += \
     abstracteditorsupport.cpp \
@@ -126,7 +127,8 @@ SOURCES += \
     stringtable.cpp \
     symbolfinder.cpp \
     symbolsfindfilter.cpp \
-    typehierarchybuilder.cpp
+    typehierarchybuilder.cpp \
+    senddocumenttracker.cpp
 
 FORMS += \
     completionsettingspage.ui \