compatibility with TypeScript

[jhuss]

on an extjs app that I working is in typescript and webpack (using ts-loader)
adding the extjs-loader module, the app keep trying to load a .js files, inspecting the code at this line:

extjs-loader/lib/loader.js

Line 58 in 8f9fc17

retVal = [prefix.replace(prefix, pathMap[prefix]) + className.replace(prefix, '').replace(/\./g, '/') + '.js'];

removing the + '.js' string concatenated at the end is working, and app load correctly

[zmagyar]

That's only working if js is listed in in webpack config. Anyway if you make a PR I'm happy to merge.

[zmagyar]

Merged PR and published under v0.0.11