Format the output of prtrace
Format the sytle of trace-giri pass

 - dyn_cast<T> to isa<T> if possible
 - Coding style
Make the INPUT of test/Makefile configurable

We change it from INPUT= to INPUT ?= to that we can specify the input of
the test cases from the command line.
Clean the visitCallInst for tracing
Use CXX to link and load the $(NAME).trace.exe

Now we can write our Tracing module in C++ style.
Specially record external calls
Don't record f used by pthread_create(f)
Store the BBStack and FNStack for each thread

We use an ordered_map to hold the BBStack and FNStack for each thread
Format the output of printed trace
Add more statements which are not slice
Add merge-return pass before the giri slicing pass

This will fix the bug brought by unreachable statement. Now the test
case 12 can pass.
Dump the BB id when no record found in trace