LongFunction存在NPE问题

[nkbaixiaojie]

com.googlecode.aviator.runtime.function.system.LogFunction类中：

若obj的值为null，则下方代码中的obj.getClass()会抛NPE异常 throw new ClassCastException("Could not cast " + obj.getClass().getName() + " to long");

[killme2008]

Good catch，欢迎提个修复 PR

[shuailung]

DoubleFunction和 BigIntFunction 都有类似的问题

[killme2008]

Fixed via https://github.com/killme2008/aviatorscript/pull/615