Becoming a member, creating new subscription bills

This component allows a user to create new transactions in order to become a member.
If he is not a member, it will create a new entry in the member table for this user and link it to the created transactions.
If he is already a member, it will update the member's entry for subscription transaction.

This component queries the DB for subscription costs and fee to become a member. (options table)
This component also queries the db to determine if the user is a member or not and adjust bill creation based on that information.

This component was also added to tab in  myaccount component

UI with success message (this screenshot was taken before localisation strings were saved, but they have been added)
![adhesionsuccess](https://cloud.githubusercontent.com/assets/3430891/5063711/495854c4-6dbf-11e4-81ee-75c90ddf0fd6.PNG)

also, right now this is unsafe because it creates a new transaction and mysql doesn't support nested transactions