错误提示：
"iPhone/iPod Touch: application executable is missing a required architecture. At least one of the following architecture(s) must be present: armv6"
按照经验，我已经在Target build setting中的Architectures增加了armv6，target os为4.0，仍然报错。
解决办法：
Xcode4.5 no longer builds binaries
for armv6. So although your settings says that they are being built, they are not.
XCode 4.5中最低的Target版本是4.3，而在4.3之后，都是armv7架构。
所以我暂时去掉了armv6，Target版本使用4.3。