QtCreator integration : git must ignore .pro and .pro.user files.

Change-Id: Ifd21679fb7dd2b5c0c3bfe7726bf2c4d19897e21
Reviewed-on: https://gerrit.libreoffice.org/17467Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>

.gitignore

@@ -123,6 +123,10 @@ DerivedData
 *.vcxproj*
 *.opensdf
 
+# QtCreator specific
+*.pro
+*.pro.user
+
 # doxygen output
 /docs