@Nicolinux: ... can I give you a suggestion ?
One very nice possibility of the new IDE (if I remember well is starting from the 1.6.5) is to have "sandboxed" independent IDE ... you can have many versions of the same/different IDE and each one is totally closed i herself.
To do that, on OS X (... where I'm) first give a unique name to your Arduino copy (eg. the last version, for me, is "Arduino 1.6.9 Portable.app"), next right click and select "Show Package Contents", next go to "Contents/Java/" and inside create a new folder named "portable" (so you have Contents/Java/portable/"). Close and restart the IDE ... you have a sandboxed IDE, totally independent from other IDE installation (so ... NO the same libraries, NO the same packages, NO the same boards, ecc.) very useful to create specific IDE installations.
If you download the IDE 1.6.9, give a unique name, make "portable" (as explained), select "Arduino MEGA 2560", open "Marlin.ino" and compile ... you should have just one warning that you can ignore
Guglielmo