1. MonoTime/MonoDelta
MonoTime: The MonoTime represents a particular point in time, relative to some fixed but unspecified reference point.
MonoDelta: The MonoDelta class represents an elapsed duration of time, the delta between two MonoTime instances.
2. CountDownLatch
This is a C++ implementation of the Java CountDownLatch
* Reduce UT binary size
Almost every module depend on ExecEnv, and ExecEnv contains all
singleton, which make UT binary contains all object files.
This patch seperate ExecEnv's initial and destory to anthor file to
avoid other file's dependence. And status.cc include debug_util.h which
depend tuple.h tuple_row.h, and I move get_stack_trace() to
stack_util.cpp to reduce status.cc's dependence.
I add USE_RTTI=1 to build rocksdb to avoid linking librocksdb.a
Issue: #292
* Update
