Allow to fetch a TFS branch independently

Hi @MakingSense/dataonix,

The idea of this change is to make our TFS fetch more quick and also mitigate issues related with switch branches or duplicated commits.

The idea is allow to fetch only one branch, from GitHub and TFS, 

* Trunk / develop: `$ git f-develop`
* Integration / integration: `$ git f-integration`
* QA / qa: `$ git f-qa`
* dspmigration / dspmigration: `$ git f-dspmigration`

if you think that it is useful, I will merge it and you have to pull the last commit from `migration` branch on `MakingSense/git-helpers` repo.