1. replace all boost::shared_ptr to std::shared_ptr
2. replace all boost::scopted_ptr to std::unique_ptr
3. replace all boost::scoped_array to std::unique<T[]>
4. replace all boost:thread to std::thread
from/to_base64 may return incorrect value when the value is null #4130
remove the duplicated base64 code
fix the base64 encoded string length is wrong， and this will cause the memory error
This CL mainly includes:
- add some methods to get thread's stats from Linux's system file in
env.
- support get thread's stats by http method.
- register page handle in BE to show thread's stats to help developer
position some thread relate problem.
