(#20994) fix incorrectly set memorysize on AIX using svmon (was set to 0)
tested on AIX 5.3, 6.1, and 7.1
(#20994) fix incorrect memoryfree fact on AIX (was set to 0)
tested on AIX 5.3, 6.1, and 7.1
(#20994) add rspec tests for memoryfree and memorysize on AIX using svmon
Merge pull request #554 from haus/ticket/stable/fix-aix-memory-facts

Cherry-pick aix memory fixes