avoid browserifying Buffer, for #39

[nlf]

No description provided.

[rlidwka]

I'd bet it will throw with ReferenceError: global is not defined in a browser.

[nlf]

I bet you're right. I'll add a guard to make sure globals exists first.

[nlf]

I completely reworked this to use the suggestion from @latentflip in #39, as well as tweaking a couple other things to make sure that stringifying weird objects works correctly (since it didn't when I added tests to get coverage on this change)

[dominykas]

I'd wrap the final return in !!( ... ) to ensure it's a bool - otherwise if isBuffer is undefined, we get undefined as the final result.