Prepare Contributor's work package with Git integration

This task is for contributors which are
GUI Users or Command Line users (with storage).

For Linux and Mac:
We offer a script that should do the following steps:

• create shortcut into tvb.simulator at package top level
• remove the contents of tvb.simulator
• to a checkout from repository passed as parameter in tvb.simulator
  Note: the scripts will receive 2 parameters, the first one either simulator or analyzers and the second is a git repository.

For Windows:

• creating shortcuts is not really possible
• so an alternative is to create a new folder in root package
• add this new folder to PYTHON_PATH and checkout TVB_Library Sources in it.

To Be decided:

• if we go with 2 versions, or implement the "Windows Solution" for all 3 distributions
• it is preferable to have a single solution (if easy to modify PYTHON_PATH).