* runtime_sigprof.cpp (freqency): 100 is also okay.
(MAX_STACK): Rename to max_stack. And disconnected with freqency.
(other functions): Rename MAX_STACK.
* README.md: Add goals, FAQ, etc.
Merge branch '4_9-plugin' into 4_9-plugin-realtime
* README.md: Add goals, FAQ, etc.
* runtime_sigprof.cpp (freqency): 100 is also okay.
(MAX_STACK): Rename to max_stack. And disconnected with freqency.
(other functions): Rename MAX_STACK.