[meta] Automate plugins update

[ccamara]

Plugins rely on manual updates, but there's no fast way to update them on an automated time-basis. There are two solutions to fix this, according to the original plugin's nature:

• Git repo that contains only one plugin -> git submodules (View Implement git submodules #6 )
• Git/SVN repo that contains several files, but not all of them are to be cloned -> create a custom script that 0) runs on a time-basis 1) downloads the whole repo, 2) copies a certain file to this repo 3) commits and pushes changes to this repo (view Script for maintaining certain files from an existing repo #7)

[ccamara]

Git sparse checkout can provide a solution to clone only a folder or file from another repository (see #10 ):

• http://www.harecoded.com/sparse-checkout-git-1329553
• http://stackoverflow.com/questions/2336580/sparse-checkout-in-git-1-7-0