Remove project-root.jam references from the documentation.

[jurko at docte dot hr]

project-root.jam references throughout the documentation should be replaces with Jamroot.

While at it the main boost project's project-root.jam file should be renamed to Jamroot.

[grafik]

Can we please stick to using names with extensions. Dealing with non-extension names on Windows is a real PITA.

[jurko.gospodnetic@…]

Updated all the examples & test cases to consistently use file names jamroot.jam & jamfile.jam. All of Boost Build's internal Jamroot & Jamfile files are now also named jamroot.jam & jamfile.jam.

I guess documentation & comments will keep the old generic Jamroot & Jamfile names but should note that their preferred actual file names are jamroot.jam & jamfile.jam.