Prior to this commit, the mount resource on AIX would not remount NFS
shares with the mount options specified. Since AIX did not read the NFS
options from the `/etc/filesystems`, the share would be remounted
without options.

This commit adds a simple check to ensure all AIX remounts are done with
the specified options including JFS2.

…retlavallee/puppet into PUP-7807/master/aix_remount_options

Building on prior work, this commit DRYs up the code in mount a bit, sharing
behavior between bsd and aix, and breaking out a couple utility methods. A test
is added to assert that on AIX, if remounts is true and options are specified,
we pass the specified options with the appropriate 'remount' command.

Signed-off-by: Moses Mendoza <moses@puppet.com>

Clarify what's happening in the #remount_with_option command.

Signed-off-by: Moses Mendoza <moses@puppet.com>