1. Support Keil MDK development environment 2. Modify EMAC driver according to the changes of lwIP API in reversion 1668 and 1669 git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1681 bbd45198-f89e-11dd-88c7-29a3b14d5316
git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1539 bbd45198-f89e-11dd-88c7-29a3b14d5316
git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1364 bbd45198-f89e-11dd-88c7-29a3b14d5316