cooker|command|event: add new command findFilesMatchingInDir

This command can be used to search each BBPATH for files in the passed
directory which have a filename matching the supplied pattern.

This is implemented for use from the GUI (to determine the available
PACKAGE_CLASSES) but has been written so as to be generically useful and
reusable.

(Bitbake rev: 2a599812a57cb0b964880a6a2b7548423497ea92)

Signed-off-by: Joshua Lock <josh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/event.py

@@ -390,6 +390,16 @@ class TargetsTreeGenerated(Event):
         Event.__init__(self)
         self._model = model
 
+class FilesMatchingFound(Event):
+    """
+    Event when a list of files matching the supplied pattern has
+    been generated
+    """
+    def __init__(self, pattern, matches):
+        Event.__init__(self)
+        self._pattern = pattern
+        self._matches = matches
+
 class ConfigFilesFound(Event):
     """
     Event when a list of appropriate config files has been generated