[BUG] Firefox Memory Leak

[python273]

(Similar to proginosko/LeechBlockNG#124)

1. Open about:memory (about:processes will also show grow of memory usage over time)
2. Measure and search set/{a8cf72f7-09b7-4cd4-9aaa-7a023bf09916}
3. Running GC clears memory (so technically not 'leak'), but still annoying

[sheepzh]

@python273 thanks for your feedback! i ll look into it

[sheepzh]

checked it already. this situation is mostly caused by frequent invokings of sendRuntimeMessage and storage.onChanged. i ll try to refactor them with multiple caching structure. hope it works