Add 'history' command to changelog; tweak ProfileVersion.__eq__().

- Add mention of the new history command to the changelog.

- Make ProfileVersion.__eq__() compare version but not path, so that it lines up
  with what __lt__() does, for simplicity.

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## 0.2.4 (unreleased)
 
+- Added an `nvd history` command for diffing successive generations of a
+  profile, issue #18.  Big thanks to Felix Uhl for the idea and implementation!
+
 - Added `--sort` option for controlling the order packages are listed in, for
   issue #17.
 

src/nvd

@@ -125,8 +125,8 @@ class ProfileVersion:
     def __eq__(self, other):
         if not isinstance(other, ProfileVersion):
             return NotImplemented
-        
-        return self._version == other._version and self._path == other._path
+
+        return self._version == other._version
 
     def path(self):
         return self._path
@@ -1040,7 +1040,7 @@ def run_history(
         )
     else:
         print(f"Contents of profile version {oldest_profile.version()} were omitted, use --list-oldest to show them.")
-    
+
     # Show diff between all profiles.
     for [base_profile, displayed_profile] in pairwise(all_profiles):
         print(f"\n--- Version {displayed_profile.version()}:")