The implement of require.register function has some problem

[zhengxiaoyao0716]

From brunch/brunch#1771

[zhengxiaoyao0716]

Well, I took a look for those source, it, emm, a bit ugly. Why we keep such a large size map named aliases? it useless.
What we need is just expand an suffix if user not given. so we just need to keep an ordered list of commonly suffix, and provide a new interface to allow plugin developer control them. Then, tried those suffix in turn in expandAlias function, that what NodeJS done .