Bug #53950 Custom JAR import doesn't handle standard JAR, confuses users

Description:
If you go to Settings->Import/Export->Custom Rule/Graph Import and point to a standard Advisor bundle (i.e. the kind you'd get by downloading a bundle from the Enterprise website), you will get an error message when trying to load the bundle.

How to repeat:
1) Install and start a Service Manager
1) Go to Settings->Import/Export->Custom Rule/Graph Import
3) In the (lower) Custom Rule/Graph Import section, browse to a standard Advisor JAR (I'll attach one for reference)
4) Click the import button
5) See an error message
6) Look in the logs and you'll see an error message like this:

Transaction com.mysql.etools.monitor.pom.hib.HibPersistence$38@5090d77c failed after 0 retries.
java.lang.RuntimeException: attribute uncompress_seconds does not exist for type innodb_compression_time
at com.mysql.etools.monitor.pom.hib.HibType.throwIfNull(HibType.java:136)
at com.mysql.etools.monitor.pom.hib.HibType.getAttribute(HibType.java:130)
at com.mysql.etools.monitor.pom.hib.HibExpressionVariable.<init>(HibExpressionVariable.java:74)
...

If you go to Settings->Global Settings and use the Advisor Bundle section on that page to import the JAR, all is well.

Suggested fix:
The underlying issue is user confusion rather than a true bug, but I think we need to handle this better.  I created a special Cluster Advisor bundle build, gave it to Andrew Morgan on the Cluster team, and he used the "custom" import and got this error.  I can easily see a customer getting confused by this as well.

In reality, the Advisor bundle I gave him is not a "custom" bundle, but rather a "standard" bundle, but how is the user to know that?  They're both JARs.  Is there some reason the "custom" import feature can't handle a "standard" JAR and vice versa?