[refactor] Use `deumdify` to build the `engine.io-client`

In this way we can control every single part of the build.
[minor] Rebuild the Engine.IO client -- version 1.4.2
[patch] Reapply the fix for the Blue Coat blocking
[patch] Reapply the utf8 patch
Merge pull request #310 from primus/deumdify

deUMDify