Defer missing dependency errors to factory execution time

[unscriptable]

We should consider deferring the detection of dependency failures when using CommonJS/node module or AMD-wrapped CommonJS modules. See this issue: amdjs/amdjs-api#21

Module authors could trap the errors inside the module code and decide how to deal with the missing dependency.

Additional benefit: this would help narrow the differences between server-side and client-side module behavior.