doc: Mention the pronunciation of "Guix".

* README: Mention pronunciation of "Guix".
* doc/guix.texi (Introduction): Likewise.

doc: Document basic package definitions.

* doc/guix.texi (Programming Interface): Add introduction.
  (Defining Packages): Populate.

guix-package: Add `--list-available'.

* guix-package.in (show-help, %options): Add `--list-available'.
  (guix-package)[process-query]: Add support for `--list-available'.
* doc/guix.texi (Invoking guix-package): Document it.
* tests/guix-package.sh: Add test.

* guix/ui.scm (location->string): New procedure.
* guix/utils.scm: Export <location>.

guix-package: Add `--list-installed'.

* guix-package.in (show-help, %options): Add `--list-installed'.
  (guix-package): Move main body to...
  [process-actions]: ... here.  New internal procedure.
  [process-query]: New procedure.
* tests/guix-package.sh: Add tests for `--list-installed'.
* doc/guix.texi (Invoking guix-package): Document it.

Turn Guix into "GNU Guix".

* configure.ac: Change package name to "GNU Guix", and bug-report
  address to `gnu-system-discuss@gnu.org'.
* doc/guix.texi: Replace "Guix" by "GNU Guix" in some places.
  (Top, Introduction): Mention "for the GNU system".
* HACKING, README: Use "GNU Guix" instead of "Guix" in some places.

doc: Document the features and `guix-package'.

* doc/guix.texi: Change the category to "Package management".  Add an
  @direntry for "Invoking guix-package".
  (Package Management): New chapter.

doc: Document `guix-build'.

* doc/guix.texi (Invoking guix-build): Populate.

doc: Remove unnecessary @ifinfo.

* doc/guix.texi: Remove @ifinfo around @dir{category,entry}.  Suggested
  by Karl Berry <karl@freefriends.org>.

doc: Add the stub of a manual.

* doc/guix.texi: New file.
* doc/fdl-1.3.texi: New file, copied from Gnulib.

* Makefile.am (info_TEXINFOS): New variable.
  (EXTRA_DIST): Add `doc/fdl-1.3.texi'.