CRM-14716 - Change default Visibility for Mailings for Public Pages.

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* CRM-14716:
  https://issues.civicrm.org/jira/browse/CRM-14716
Merge pull request #3314 from davecivicrm/CRM-14716

CRM-14716 - Change default Visibility for Mailings for Public Pages.
Fix incomplete comment and add placeholder to duration_unit in Membership Type form.
Merge pull request #3316 from davecivicrm/commentAndDropdownFix

Fix incomplete comment and add placeholder to duration_unit in Membershi...
minor code tidyups
Merge pull request #3315 from eileenmcnaughton/codetidying

Codetidying - remove a couple of unused params
CRM-14197 pass line items & isTest into renewMembership (derive at form level
param fix & clarify object to pass to updateRecurmembership fn

declare membershipContributionID & use that

remove  param

don't check for empty on  - would have had an error

remove unrequired param

set membershipContribution directly as required
towards CRM-14197 pass lineitems & isTest into renewMembership

remove minor code duplication, ensure  set to form value
clarify creation of creating a separate membership contribution
minor cleanups
refactor processing of secondary transaction into separate function
evaluate form contribution TypeID on form function
refactor creation of membership_payment records into shared function
use try catch rather than passing errors as a reference
refactor out createOrRenewMembership function
share create membership function & move compiling errors into a separate function
separate form level part of renewal from bao part using an outer wrapper function
further consolidation on membership creation
comment fixes