use dict syntax for app instances to allow API usage with plain dicts

Since metadata files are now YAML, programs should be able to just read in
the .yml files, then use them with fdroidserver methods without having to
know about the App class.  The App class just provides syntactic sugar by
allowing dict keys to be accessed as attributes.

fdroidserver/index.py

@@ -358,7 +358,7 @@ def make_v0(apps, apks, repodir, repodict, requestsdict, fdroid_signing_key_fing
     for appid, appdict in apps.items():
         app = metadata.App(appdict)
 
-        if app.Disabled is not None:
+        if app.get('Disabled') is not None:
             continue
 
         # Get a list of the apks for this app...

fdroidserver/update.py

@@ -247,13 +247,13 @@ def update_wiki(apps, apks):
         buildfails = False
         for apk in apks:
             if apk['packageName'] == appid:
-                if str(apk['versionCode']) == app.CurrentVersionCode:
+                if str(apk['versionCode']) == app.get('CurrentVersionCode'):
                     gotcurrentver = True
                 apklist.append(apk)
         # Include ones we can't build, as a special case...
         for build in app.get('Builds', []):
             if build.disable:
-                if build.versionCode == app.CurrentVersionCode:
+                if build.versionCode == app.get('CurrentVersionCode'):
                     cantupdate = True
                 # TODO: Nasty: vercode is a string in the build, and an int elsewhere
                 apklist.append({'versionCode': int(build.versionCode),
@@ -272,7 +272,7 @@ def update_wiki(apps, apks):
                                     'versionName': build.versionName,
                                     'buildproblem': "The build for this version appears to have failed. Check the [[{0}/lastbuild_{1}|build log]].".format(appid, build.versionCode),
                                     })
-        if app.CurrentVersionCode == '0':
+        if app.get('CurrentVersionCode') == '0':
             cantupdate = True
         # Sort with most recent first...
         apklist = sorted(apklist, key=lambda apk: apk['versionCode'], reverse=True)
@@ -1912,7 +1912,7 @@ def apply_info_from_latest_apk(apps, apks):
             if app.get('Name') is None:
                 app['Name'] = bestapk['name']
             app['icon'] = bestapk['icon'] if 'icon' in bestapk else None
-            if app['CurrentVersionCode'] is None:
+            if app.get('CurrentVersionCode') is None:
                 app['CurrentVersionCode'] = str(bestver)
 
 
@@ -1931,8 +1931,8 @@ def archive_old_apks(apps, apks, archapks, repodir, archivedir, defaultkeepversi
         currentVersionApk = None
         for apk in apk_list:
             if apk['packageName'] == appid:
-                if app.CurrentVersionCode is not None:
+                if app.get('CurrentVersionCode') is not None:
-                    if apk['versionCode'] == common.version_code_string_to_int(app.CurrentVersionCode):
+                    if apk['versionCode'] == common.version_code_string_to_int(app['CurrentVersionCode']):
                         currentVersionApk = apk
                         continue
                 apkList.append(apk)
@@ -1946,8 +1946,8 @@ def archive_old_apks(apps, apks, archapks, repodir, archivedir, defaultkeepversi
 
     for appid, app in apps.items():
 
-        if app.ArchivePolicy:
+        if app.get('ArchivePolicy'):
-            keepversions = int(app.ArchivePolicy[:-9])
+            keepversions = int(app['ArchivePolicy'][:-9])
         else:
             keepversions = defaultkeepversions