Allow adding multiple books to running calibre

Allow adding multiple books to an already running calibre by passing
multiple file arguments to calibre.exe. Also change the .desktop file in
linux to indicate calibre can accept file arguments. Fixes #1207518 [Calibre is invisible in Ubuntu 13.04 "Open with" dialog](https://bugs.launchpad.net/calibre/+bug/1207518)

src/calibre/gui2/main.py

@@ -401,8 +401,9 @@ def communicate(opts, args):
         shutdown_other(t)
     else:
         if len(args) > 1:
-            args[1] = os.path.abspath(args[1])
-        t.conn.send('launched:'+repr(args))
+            args[1:] = [os.path.abspath(x) if os.path.exists(x) else x for x in args[1:]]
+        import json
+        t.conn.send('launched:'+json.dumps(args))
     t.conn.close()
     raise SystemExit(0)
 

src/calibre/gui2/ui.py

@@ -520,11 +520,12 @@ def another_instance_wants_to_talk(self):
         except Empty:
             return
         if msg.startswith('launched:'):
-            argv = eval(msg[len('launched:'):])
-            if len(argv) > 1:
-                path = os.path.abspath(argv[1])
-                if os.access(path, os.R_OK):
-                    self.iactions['Add Books'].add_filesystem_book(path)
+            import json
+            argv = json.loads(msg[len('launched:'):])
+            if isinstance(argv, (list, tuple)) and len(argv) > 1:
+                files = [os.path.abspath(p) for p in argv[1:] if not os.path.isdir(p) and os.access(p, os.R_OK)]
+                if files:
+                    self.iactions['Add Books'].add_filesystem_book(files)
             self.setWindowState(self.windowState() &
                     ~Qt.WindowMinimized|Qt.WindowActive)
             self.show_windows()

src/calibre/linux.py

@@ -833,7 +833,7 @@ def opts_and_exts(name, op, exts, cover_opts=('--cover',), opf_opts=(),
 GenericName=Viewer for LRF files
 Comment=Viewer for LRF files (SONY ebook format files)
 TryExec=lrfviewer
-Exec=lrfviewer %F
+Exec=lrfviewer %f
 Icon=calibre-viewer
 MimeType=application/x-sony-bbeb;
 Categories=Graphics;Viewer;
@@ -847,7 +847,7 @@ def opts_and_exts(name, op, exts, cover_opts=('--cover',), opf_opts=(),
 GenericName=Viewer for E-books
 Comment=Viewer for E-books in all the major formats
 TryExec=ebook-viewer
-Exec=ebook-viewer %F
+Exec=ebook-viewer %f
 Icon=calibre-viewer
 Categories=Graphics;Viewer;
 '''
@@ -857,7 +857,7 @@ def opts_and_exts(name, op, exts, cover_opts=('--cover',), opf_opts=(),
 [Desktop Entry]
 Version=1.0
 Type=Application
-Name=calibre
+Name=calibre %F
 GenericName=E-book library management
 Comment=E-book library management: Convert, view, share, catalogue all your e-books
 TryExec=calibre