bitbake/lib/bb/parse:

bitbake/lib/bb/parse:
    -Implement the 'require' keyword in bitbake. The semantic
     inherits the semantic of include.
     It only differs in the way missing files are handled.
     Require will raise a ParseError when a 'required' file
     could not be found.

     -We add a new keyword and scan for it
     -We change the include method to carry an additional parameter