Update readme for 2.4.0 release

README.md

@@ -45,6 +45,8 @@ The manual (including install instructions) can be found in the doc/ directory.
 
 ## Important update notes
 
+*2.4.0 and up*: A lot of changes were made to the normalization, and the performance under Python 2.x was significantly improved. The average parsing time under Python 2.7 has dropped by 94% (!), and on my system averages out at 18ms. Performance under Python 3.x is [unchanged](https://github.com/joepie91/python-whois/issues/27). `pythonwhois` will now expand a lot of abbreviations in normalized mode, such as airport codes, ISO country codes, and US/CA/AU state abbreviations. The consequence of this is that the library is now bigger (as it ships a list of these abbreviations). Also note that there *may* be licensing consequences, in particular regarding the airport code database. More information about that can be found below.
+
 *2.3.0 and up*: Python 3 support was fixed. Creation date parsing for contacts was fixed; correct timestamps will now be returned, rather than unformatted ones - if your application relies on the broken variant, you'll need to change your code. Some additional parameters were added to the `net` and `parse` methods to facilitate NIC handle lookups; the defaults are backwards-compatible, and these changes should not have any consequences for your code. Thai WHOIS parsing was implemented, but is a little spotty - data may occasionally be incorrectly split up. Please submit a bug report if you run across any issues.
 
 *2.2.0 and up*: The internal workings of `get_whois_raw` have been changed, to better facilitate parsing of WHOIS data from registries that may return multiple partial matches for a query, such as `whois.verisign-grs.com`. This change means that, by default, `get_whois_raw` will now strip out the part of such a response that does not pertain directly to the requested domain. If your application requires an unmodified raw WHOIS response and is calling `get_whois_raw` directly, you should use the new `never_cut` parameter to keep pythonwhois from doing this post-processing. As this is a potentially breaking behaviour change, the minor version has been bumped.