Add output_limit configuration option for sandbox filter.
diff --git a/heka/files/toml/filter/sandbox.toml b/heka/files/toml/filter/sandbox.toml
index 9608e52..17de658 100644
--- a/heka/files/toml/filter/sandbox.toml
+++ b/heka/files/toml/filter/sandbox.toml
@@ -16,6 +16,9 @@
 {%- if filter.hostname is defined %}
 hostname = "{{ filter.hostname }}"
 {%- endif %}
+{%- if filter.output_limit is defined %}
+output_limit = {{ filter.output_limit|int }}
+{%- endif %}
 
 {%- if filter.config is defined %}
 [{{ filter_name }}_filter.config]