Bug fix on message_center
Added number of won sponsorships in an event.
Remove gp_sync field.

- Remove useless gp_sync field
- Bug fixes
- Small code improvements
- To be tested...
GIFT_TYPES Names are in one place and translated.

- Plus corrections on gp_sync. Contracts that are not compatible with
  GP can not be created.
- Standardization of error messages in gp_sync module
Ability to sponsor delegated, on internet children

- [NEW] Method to remove children from the website
Replace Analytic Distributions by Analytic Accounts in Events,Origins
Fixed activation of contracts
Fixed analytic account bug
Several bug fixes...
Translations bug fixed
Add analytic accoun to move lines
Invoice generation is not synchronized to GP.
New features and bug fixes.
PEP8 + Origin creation fixed
Don't prevent to create Projects from Events. Other bug fixes.
Small corrections
Code refactoring

- Bug fixed where contracts ended with 'depart_child' as ending
  reason were not correctly updated in GP.
- Code refactoring
Code refactor
Fixed PEP8 errors
Code corrections

- [New] Sponsorship and General Fund are automatically selected
        for new contracts.
- [New] Contract names are more friendly
- [FIX] Various code fixes