RFR: 8226575: OperatingSystemMXBean should be made container aware

[Daniil Titov]

Please review the change that makes OperatingSystemMXBean methods return container specific information
rather than the host based data.

The webrev [1] is based on the code Andrew and Severin initially provided with some additional changes and combined
 with the spec update David made [3].

The webrev corrects the implementation for the free/total swap methods as Bob noted to subtract the total
and free memory from the returned values.

It also corrects getCpuLoad() implementation, as Bob advised, to cover the case when CPU quotas are not active.

The webrev also takes into account the case when java.security.AccessControlException exception is thrown
during the initialization of the container subsystem ( e.g.  when java.policy doesn’t grant "read" access to
 "/proc/self/mountinfo" file).

CSR for the spec changes [3] is approved.

Testing: Mach5 tiers1, tiers2, tiers3, tier4, tier5 (including open/test/hotspot/jtreg/containers/docker),  and tier6 tests passed .

[1] Webrev:  http://cr.openjdk.java.net/~dtitov/8226575/webrev.02/ 
[2] Jira issue :https://bugs.openjdk.java.net/browse/JDK-8226575 
[3] CSR https://bugs.openjdk.java.net/browse/JDK-8228428 

Thank you,
-Daniil