add gitignore
add class Finally
add common header Common.h
add class Exception with backtrace info
add class Thread (Pthread on Linux)
fix make class Thread noncopyable
fix use noncopyable inheritance to forbid copying object
add class Mutex & MutexGuard
add Class Condition to work with Mutex
add support OS X
add comments
comment a trivial bugs
add statistics for class Thread
fix put selftid into the unnamed namespace
Merge remote-tracking branch 'github/master'