Add: Software update directory for aix 6.1 powerpc

Ref: https://dev.cfengine.com/issues/6583

In order for the binary upgrade policy in `update/update_bins.cf` to
work for aix the specific aix version is needed.
Add: Feature to disable checking of cf_promises_validated

Ref: https://dev.cfengine.com/issues/6688

Make it easy to have clients always scan for any changes and update
accordingly.
Merge pull request #340 from nickanderson/option_cf_promises_validated

Add: Feature to disable checking of cf_promises_validated
Merge pull request #327 from nickanderson/redmine/6583

Add: Software update directory for aix 6.1 powerpc
Explain permissive bodies

@nickanderson copying this to 3.6 etc. is up to you...
Merge pull request #342 from tzz/patch-1

Explain permissive bodies
Add: More clear explination of permissive package methods

This is documented in the 3.7 set already, bringing back into 3.6 set
Merge pull request #343 from nickanderson/document_permissive_in_36

Add: More clear explination of permissive package methods
redhat_4 class does not exist on centos_4
When there was an update in master_software_updates, the clients would always refresh the package list. With this change the clients only update the package list weekly. The update will not take longer with this change.
Change: Move mailto and mailfrom settings to def.cf

This should make  policy framework upgrades slightly easier by limiting the number
of shipped files users are required to touch.
Change: Tighten reference to runlog

Using sys.host to identify the correct runlog is error prone as sys.host
is ambiguous and may be either the short or long hostname. The runlog
file is always named for the shorthostname so we should use sys.uqhost
when referencing it or it may grow without bound.
Merge pull request #346 from nickanderson/redmine/6563

Change: Tighten reference to runlog
Merge pull request #345 from nickanderson/redmine/6702

Change: Move mailto and mailfrom settings to def.cf
Change: Move smtpserver setting for cf_execd to def

mailto and mailfrom are already in def. It makes sense to keep the
smtpserver with them. This is intended to make policy framework upgrades
slightly easier.
Merge pull request #349 from nickanderson/move_smtpserver

Change: Move smtpserver setting for cf_execd to def
Simplify script - no change in functionality.
Merge pull request #351 from jimis/tarball

Simplify script - no change in functionality.
Fix script exiting with error when NO_CONFIGURE was set.
Merge pull request #352 from jimis/tarball

Fix script exiting with error when NO_CONFIGURE was set.