Expose context in OP initialize and finalize

Expose the context to the initialize and finalize functions for Output
Processors. This was found to be necessary for the upcoming PostgreSQL
Output Processor.

wa/framework/output_processor.py

@@ -40,10 +40,10 @@ class OutputProcessor(Plugin):
                 msg = 'Instrument "{}" is required by {}, but is not installed.'
                 raise ConfigError(msg.format(instrument, self.name))
 
-    def initialize(self):
+    def initialize(self, context):
         pass
 
-    def finalize(self):
+    def finalize(self, context):
         pass
 
 
@@ -104,13 +104,13 @@ class ProcessorManager(object):
         for proc in self.processors:
             proc.validate()
 
-    def initialize(self):
+    def initialize(self, context):
         for proc in self.processors:
-            proc.initialize()
+            proc.initialize(context)
 
-    def finalize(self):
+    def finalize(self, context):
         for proc in self.processors:
-            proc.finalize()
+            proc.finalize(context)
 
     def process_job_output(self, context):
         self.do_for_each_proc('process_job_output', 'Processing using "{}"',