Android中webview：软键盘弹出引起的各种不适

引：

http://blog.csdn.net/achellies/article/details/7034756

http://blog.csdn.net/u010681361/article/details/50904738

http://blog.csdn.net/cxt528440900/article/details/47035205

http://www.cnblogs.com/jamkier/p/SoftInputMode.html