修正apr在vs2013下编译出现：

apr_atomic.obj : error LNK2019: unresolved external symbol __InterlockedIncrement referenced in function _apr_atomic_inc32@4
apr_atomic.obj : error LNK2019: unresolved external symbol __InterlockedExchangeAdd referenced in function _apr_atomic_add32@8
apr_atomic.obj : error LNK2019: unresolved external symbol __InterlockedExchange referenced in function _apr_atomic_set32@8
apr_atomic.obj : error LNK2019: unresolved external symbol __InterlockedDecrement referenced in function _apr_atomic_dec32@4
apr_atomic.obj : error LNK2019: unresolved external symbol __InterlockedCompareExchange referenced in function _apr_atomic_cas32@12

这是一个兼容问题：网上找到如下描述
https://groups.google.com/forum/#!topic/UniMRCP/Iybpn51UYnI

注意：
修改后的版本vc6可能不能编译通过。