Require higher privilege for some operations

[gothub]

This PR had the following changes:

For issue #9, these changes were made: CustomersResource

• listCustomers()
  • requested customer subject = caller subject, unless isBookkeeperAdmin() is true
  • isBookkeeperAdmin() true if listing all customers
• delete()
  • isBookkeeperAdmin() must be true OrdersResource
• delete()
  • isBookkeeperAdmin() must be true ProductsResource
• create()
  • isBookkeeperAdmin() must be true
• update()
  • isBookkeeperAdmin() must be true
• delete()
  • isBookkeeperAdmin() must be true UsagesResource
• delete()
  • isAdmin must be true
  • doesn't check isBookkeeperAdmin() QueuesResource
• create()
  • isBookkeeperAdmin() must be true
• update()
  • isBookkeeperAdmin() must be true
• delete()
  • isBookkeeperAdmin() must be true

For issue #36, these changes were made:

• updated ./api/Quota.java to disallow no value for subscriptionId
• minor update to param declaration order to be same as database order

For issue #38, these changes were made:

• update QuotaStore.update(), UsageStore.update() annotations to fix update problem

For issue #14, these additional changes were made:

• additional changes needed for the column renaming (quota.name -> quota.quotaType)