Use PlistReader to decrease burden on recipe creators

Here's a processor that could be added in order to prevent recipe creators from having to know/look up the bundle identifier of the app:

```

Processor
PlistReader
Arguments

info_path
%pathname%/%NAME%.app/Contents/Info.plist
plist_keys

CFBundleIdentifier
fw_app_bundle_id
CFBundleShortVersionString
version



```

That's for a dmg download like Adium. The following would be for a zip download like Evernote:

```

Processor
PlistReader
Arguments

info_path
%RECIPE_CACHE_DIR%/%NAME%/%NAME%.app/Contents/Info.plist
plist_keys

CFBundleIdentifier
fw_app_bundle_id
CFBundleShortVersionString
version



```

With that in place, you could skip the `fw_app_bundle_id` argument in the FileWaveImporter processor entirely.

Notice it also looks up the `%version%` but that's only useful if another upstream processor doesn't already provide the version number (e.g. SparkleUpdateInfoProvider usually does provide version).

Start at the FileWaveImporter processor and the PlistReader processor entry point, using the Adium DMG and Evernote ZIP examples in the issue as the intended paths. Check how plist_keys supplies fw_app_bundle_id and version, then verify that FileWaveImporter no longer needs an explicit fw_app_bundle_id when those values are available.

Written by the indexing model from the issue text.