add default 'all' environment

[aegyed91]

@thlorenz Regarding #2, i monkey patch-ed to allow 'all' as a default environment.

It is frustrating that all the sources on the web mention this all environment default flag but its actually doesn't work.

f.e:

• http://stackoverflow.com/a/29224523/1949274
• https://terinstock.com/blog/2014/02/27/replacing-packages-in-a-browserify-bundle.html

[aegyed91]

@thlorenz ping

[tgabi333]

+1