[Pharo-project] Migrating ProfStef from Squeaksource to PharoExtras

[Stéphane Ducasse]

Hi guys

I'm migrating ProfStef to SmalltalkHub/PharoExtras.
I'm also copying the configurationOf from MetacelloRepository and I will produce
a new configuration for 2.0 and for SmalltalkHub.

Stef