wordpress updates which files have been changed?

dear wordpress forum users,

whenever a wordpress update comes out … where can i find a list of files which have been changed in the updated version?

the reason i ask … i made a whole lot of custom hacks to the wordpress core system as my client requested a sort of very special setup which was not possible to do with a plugin …

so quite a few wordpress core files have been modified and i find it quite easy to update if i get a list of files which have been changed in the update release …

is there a list of files which have been changed in the update release version? if so … where can i find that list??

thanks a million ?? and have fun with wordpress!

greetings
becki