7.0 connector magento rma

Add module for synchronizing RMA
We have a basic module on magento side https://code.launchpad.net/~magentoerpconnect-core-editors/magentoerpconnect/magento-rma-module

Question : maybe we should move all magento-module in github too? (under OCA?)


```formated_date``` is used only for the logger? the code is duplicated with the one in `search`, why not log into `search`?