gnu: emacs-beancount: Restructure package, now independent of beancount.

* gnu/packages/finance.scm (emacs-beancount): Restructure package, now
independent of beancount and in its own git repository.  Note that there is no
version number for the now independent code tree, so unfortunately this might
look like a "version downgrade" to some users as it switched from being
beancount's revision number to being a git-derived version number.

gnu/packages/finance.scm

@@ -1668,25 +1668,30 @@ define financial transaction records in a text file, read them in memory,
 generate a variety of reports from them, and provides a web interface.")
     (license license:gpl2)))
 
-;; The beancount source ships with elisp in a subdirectory
 (define-public emacs-beancount
-  (package
-    (inherit beancount)
-    (name "emacs-beancount")
-    (build-system emacs-build-system)
-    (arguments
-     `(#:tests? #f ;no tests
-       #:phases
-       (modify-phases %standard-phases
-         (add-before 'install 'chdir-emacs
-           (lambda _
-             (chdir "editors/emacs")
-             #t)))))
-    (inputs '())
-    (native-inputs '())
-    (synopsis "Emacs mode for beancount")
-    (description
-      "Emacs-beancount is an Emacs mode for the Beancount accounting tool.")))
+  ;; Note that upstream has not made any release since this project moved
+  ;; into its own repository (it was originally part of beancount itself)
+  (let ((commit "dbafe6a73d90c1f64d457b356b9dbb43499f70d5")
+        (revision "0"))
+    (package
+      (name "emacs-beancount")
+      (version (git-version "0.0.0" revision commit))
+      (source
+       (origin
+         (method git-fetch)
+         (uri (git-reference
+               (url "https://github.com/beancount/beancount-mode")
+               (commit commit)))
+         (sha256
+          (base32
+           "0v9bws2gv5b00x829p7hrcxqgdp7iwxvv1vhfjka81qrw6w1fvjw"))
+         (file-name (git-file-name name version))))
+      (build-system emacs-build-system)
+      (home-page "https://github.com/beancount/beancount-mode")
+      (synopsis "Emacs mode for Beancount")
+      (description
+       "Emacs-beancount is an Emacs mode for the Beancount accounting tool.")
+      (license license:gpl3+))))
 
 (define-public hledger-web
   (package