add fireapp_before_build & fireapp_after_build callback

config.rb example:

fireapp_before_build = lambda { |build_path|
  App.alert "Before buepp_before_buildld: #{build_path}"
}

fireapp_after_build = lambda { |build_path|
  App.alert "after build: #{build_path}"
}

src/compass_patch.rb

@@ -53,13 +53,22 @@ def self.strip_trailing_separator(*args)
   Configuration.add_configuration_property(:fireapp_minifyjs_on_build, nil) do
     false
   end  
+
   Configuration.add_configuration_property(:fireapp_always_report_on_build, nil) do
     true
   end
+
   Configuration.add_configuration_property(:fireapp_disable_linecomments_and_debuginfo_on_build, nil) do
     true
   end
 
+  Configuration.add_configuration_property(:fireapp_before_build, nil) do
+    nil
+  end
+
+  Configuration.add_configuration_property(:fireapp_after_build, nil) do
+    nil
+  end
 
   # default sass_options is nil
   Configuration.add_configuration_property(:sass_options, nil) do

src/project_builder.rb

@@ -1,4 +1,3 @@
-
 require 'tilt'
 
 class ProjectBuilder
@@ -163,6 +162,8 @@ def build_static_file(release_dir, blacklist)
 
   def build(build_path)
 
+    Compass.configuration.fireapp_before_build.call(build_path) if Compass.configuration.fireapp_before_build
+
     Tray.instance.stop_livereload
     Tray.instance.stop_watcher
 
@@ -179,6 +180,8 @@ def build(build_path)
       yield msg
     end
 
+    Compass.configuration.fireapp_after_build.call(build_path) if Compass.configuration.fireapp_after_build
+
     Tray.instance.rewatch
 
     return release_dir