Thread implementation done.
Move Timer class.
Add comments.
Add several common libs.
Add namespace macros.
Use forward declaration to replace head file inclusion.
Add common definition head file.
Use macro to declare namespace.
Rename the define name to a correct one.
Use macro to declare namespace.
Move Map out of XCF head file.
Move common typedef & macro def into Common.h, and make XCF.h as an third party usage common head file.
Move common typedef & macro def into Common.h, and make XCF.h as an third party usage common head file.
Fix indent.
Fix Thread constructor issue, move logics into function Thread::init().
Add Thread::process to handle the real logics, and expose run function to start the thread loop, and also give an default implementation of function run.
Add thread status check function.
Remove unnecessary lock & unlock by lock object value.
Use thread to handle libev event loop.
Adjust create thread order.