MailHandler should catch ServiceConfigurationError

JakaraMail 1.6.6 MailHandler test fails when running under JDK 1.7 with the following:
```
Testcase: testCloseContextClassLoader(com.sun.mail.util.logging.MailHandlerTest): Caused an ERROR
javax.mail.Provider: Provider com.sun.mail.imap.IMAPProvider not found
java.util.ServiceConfigurationError: javax.mail.Provider: Provider com.sun.mail.imap.IMAPProvider not found
at java.util.ServiceLoader.fail(ServiceLoader.java:231)
at java.util.ServiceLoader.access$300(ServiceLoader.java:181)
at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:365)
at java.util.ServiceLoader$1.next(ServiceLoader.java:445)
at javax.mail.Session.loadProviders(Session.java:964)
at javax.mail.Session.(Session.java:254)
at javax.mail.Session.getInstance(Session.java:281)
at com.sun.mail.util.logging.MailHandler.initSession(MailHandler.java:3448)
at com.sun.mail.util.logging.MailHandler.writeLogRecords0(MailHandler.java:2823)
at com.sun.mail.util.logging.MailHandler.writeLogRecords(MailHandler.java:2790)
at com.sun.mail.util.logging.MailHandler.close(MailHandler.java:853)
at com.sun.mail.util.logging.MailHandlerTest.testCloseContextClassLoader0(MailHandlerTest.java:2295)
at com.sun.mail.util.logging.MailHandlerTest.testCloseContextClassLoader(MailHandlerTest.java:2273)
```
Steps to reproduce the behavior:
1. Install JDK 7.
2. Run the logging-mailhander tests.

In the field, the workaround would be to add a MailHandler.verify property to the logging properties. The documentation already suggests this.

This appears to be a regression from `GH 323 Support loading protocol providers using ServiceLoader`. This does not occur under JDK8 and later due to https://bugs.openjdk.java.net/browse/JDK-7198496

The MailHandler should be patched to:

1. Catch ServiceConfigurationError and adapt it so it can be reported to the error manager. This is need to support JavaMail versions without the fix for https://github.com/eclipse-ee4j/mail/issues/548
2. The context classloader needs to be adjusted during close and other method to support the service loader.

Overall, this shows that there is a gap in testing because project is not running all tests under each major version of the JDK.