Alert the user to which novelWriter version the file was saved with.

nw/core/project.py

@@ -382,8 +382,9 @@ class NWProject():
             self.makeAlert((
                 "Unknown or unsupported %s project file format. "
                 "The project cannot be opened by this version of %s. "
+                "The file was saved with novelWriter version %s."
             ) % (
-                nw.__package__, nw.__package__
+                nw.__package__, nw.__package__, appVersion
             ), nwAlert.ERROR)
             return False
 

sample/nwProject.nwx

@@ -1,13 +1,13 @@
 <?xml version='1.0' encoding='utf-8'?>
-<novelWriterXML appVersion="0.10.0rc1" hexVersion="0x001000c1" fileVersion="1.1" timeStamp="2020-06-27 17:00:02">
+<novelWriterXML appVersion="0.10.0rc1" hexVersion="0x001000c1" fileVersion="1.2" timeStamp="2020-06-27 17:29:20">
   <project>
     <name>Sample Project</name>
     <title>Sample Project</title>
     <author>Jane Smith</author>
     <author>Jay Doh</author>
-    <saveCount>591</saveCount>
+    <saveCount>593</saveCount>
     <autoCount>103</autoCount>
-    <editTime>24557</editTime>
+    <editTime>24563</editTime>
   </project>
   <settings>
     <doBackup>False</doBackup>