Release V4.1

This release fixes issues with / and \ in windows
Adds the possibility to use library json's
Fixes the update of json (well in V4.0 updates didn't happen)
Updates the arduino version define
Better support for version control, renaming projects, moving workspaces and eclipse runtime
New icons
New menu entries in the arduino menu
Windows 32 and 64 bit contain jre (no need to install java)