license: hashes of freeform licenses are stored in the database and these hashes...

license: hashes of freeform licenses are stored in the database and these hashes used for auto-acceptance.

freeform licenses may be files, or may be the contents of the License:
field in the R DESCRIPTION.  such text is mapped to lower case and all
space characters are compressed and mapped to a single space.

a nicer interface for adding these freeform licenses is introduced.
after reviewing the license, its hash may be added as follows:

$ cran2deb license
license> add uroot gpl
(maps hash of whatever freeform license uroot has to gpl)
...
$ cran2deb build uroot
(success is assured!)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/cran2deb@73 edb9625f-4e0d-4859-8d74-9fd3b1da38cb