[copyright] Copyright assignment to the FSF

Thanks to Donald Robertson III for his help and guidance during this
process.
Added GNU to ease.js license notice in README.md
Copyright assignment to the FSF

Copyright for the GNU ease.js project has been assigned to the Free Software
Foundation. This allows the FSF to enforce the project licenses, which is
something that I lack the time and money to do. It further ensures, through
the contract I signed with the FSF, that all distrbutions of GNU ease.js,
and all derivatives, will always ``be on terms that explicitly and
perpetually permit anyone possessing a copy of the work to which the terms
apply, and possessing accurate notice of these terms, to redistribute copies
of the work to anyone on the same terms'' and that the project ``shall be
offered in the form of machine-readable source code''.

Consequently, any contributors to the project (aside from changes deemed to
be trivial) will be required to assign copyright to the FSF; this puts GNU
ease.js on a firm legal ground to prevent complicating enforcement.
Contributors can rest assured that the code they contribute will always
remain free (as in freedom).

I thank Donald Robertson III of the FSF for his help and guidance during
this process.