at least gcc 4.4 is now the required compiler!

we can safely use what c++11 feature provided by gcc 4.4, gcc 4.4 is also what centos6 provided default compiler
travis: apply fix for boost with gcc 4.6.3
now comes the real fix for the mail sender!
decltype is not supported by gcc 4.4.7
很重要的一次修正

[ci skip]
update sqlite to 3.8
Revert "定义 BOOST_SP_DISABLE_THREADS 使用非原子操作的 shared_ptr , 减少引用计数的开销."

This reverts commit bad9cd466b9985e27f09e34a76f26ff5180cec62.

在 gcc 4.4.7 的 centos vps 上测试，观察到了 shared_ptr
因为线程不安全导致的问题。
code style

[ci skip]
update cookie_mgr to use new avhttp utils
Revert "at least gcc 4.4 is now the required compiler!"

This reverts commit 3125c7687120f6ab92ae1fcec57454ac26a231c5.

gcc 4.6 is populer! but boost 1.54 can't be compiled with gcc 4.6.X when
c++11 mode is enabled.
update with new avboost
sync avhttp
delete clean_cache, there is no longer needed

move loop code to webqq_loop.cpp
some name tweak
remove update_group_list as webqq member function
fix nick fromat, reported by huntxu
pull soci fix  :)
with new soci fix, it is now the time to remove sqlite3_enable_shared_cache
Merge pull request #8 from avplayer/master

Merge  from avplayer:master