Various fix

Hello,

following latest commits i found out several difficulties while running tests. 
Now it creates a specific test working directory and run test within it.
And btw it stops to garbage my local setup.

Also, i found out the require's cache was not clean when applications are reloaded.
I think this could be useful in case the user remove / re install an app, for whatever difficulties encountered.

thanks !
In that case, how about making private variable. Because here they are still accessible to everyone.

?