Plugin check should be based on original JAR date, not on unzip date
Plugin update checking is based on the date the plugin folder was updated and not based on the date of the original JAR file. We may need to store the date that the JAR was unzipped. Alternatively, we could use the plugin meta-data itself to do update checking (this could require) some changes.
Note that plugins downloaded from the admin console will not have the original date of the jar file. The date of the jar file will be the one when the plugin was downloaded.
Gato sent me a link a couple weeks back about preserving dates when unziping files from Java. Need to find that to see if we can use it to solve this issue...