(#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
(packaging) Pass --man to install.rb to get man pages in Debian lucid and older
Merge pull request #565 from shrug/stable

(packaging) Pass --man to install.rb to get man pages in Debian lucid and older
(#22622) External output defaults to empty string

 - Previously, if an external fact generated empty output, parse would
   be called with a nil, which cannot have each_line called on it, and
   would cause Facter to crash.  This sets a reasonable default for
   external command output to the empty string
(#22622) Resolution.exec returns '' instead of nil

 - Digging up existing calls to each_line yielded some unusual
   functionality where empty strings from output were returned as nil
   instead of ""
 - Uptime appeared to be the only existing fact dependent on this
   behavior and code / tests were updated accordingly
 - With Resolution.exec guaranteed to always return an empty string,
   some extraneous null checks could be stripped