* guix/profiles.scm (<manifest-entry>)[path]: Rename to...
[item]: ... this. Update users.
(manifest->sexp): Rename to...
(manifest->gexp): ... this. Return a gexp.
(lower-input): Remove.
(profile-derivation): Remove 'store' parameter, and turn into a
monadic procedure.
[inputs]: New variable.
[builder]: Turn into a gexp.
Replace call to 'build-expression->derivation' with call to
'gexp->derivation'.
* guix/scripts/package.scm (link-to-empty-profile): Adjust call to
'profile-derivation', and wrap it in 'run-with-store'.
(show-what-to-remove/install): Rename 'path' to 'item'. Check whether
ITEM is a package, and return its output path if it is.
(input->name+path): Remove.
(options->installable): Set 'item' to P.
(guix-package): Adjust call to 'profile-derivation'.
* tests/profiles.scm (guile-2.0.9): Change 'path' to 'item'.
Fixes <http://bugs.gnu.org/15756>.
* guix/profiles.scm (<manifest-pattern>): New record type.
(remove-manifest-entry): Remove.
(entry-predicate, manifest-matching-entries): New procedures.
(manifest-remove): Accept a list of <manifest-pattern>.
(manifest-installed?): Replace 'name' parameter by 'pattern', a
<manifest-pattern>.
* guix/scripts/package.scm (options->removable): Return a list of
<manifest-pattern>.
(guix-package)[process-action]: Use 'manifest-matching-entries' to
compute the list of packages to remove.
* tests/profiles.scm: New file.
* Makefile.am (SCM_TESTS): Add it.
