With the previous versions of cake - you'd install cake in your path and
therefore when executed the pwd was a variable.
With the creation of app/Console/cake this is not true any more, and
copying the existing use of `pwd` for app means there is an implicit
assumption that it will always and only be ran from the app dir. If it
is ran from elsewhere - it's as if the core lib/Cake/Console/cake
had been run (app dir is "missing" no boostrap, no app-plugins etc.)
With this change, all of these act exactly the same:
cd ~/root/app
Console/cake
cd ~/root/app/Console
./cake
cd ~/root
app/Console/cake
cd /anywhere
~/root/app/Console/cake
Splice the ROOT path into the include_path for console apps.
This allows users to override the system include_path with a local
version of CakePHP.
Fixes#2613
