Replace url module with lighter self-contained parser

[fregante]

Makes the package lighter in both node and the browser.

80KB -> 36KB (saves 55%)

80KB -> 13KB (saves 83% when combined with #25)

I was initially going to keep this as a fork, considering that using url might be preferred in node, but seeing that there are 1127 passing tests I thought of making a PR instead.

[zkat]

I'm going to reject this commit: compatibility with Node itself is higher priority to us than reducing bundle sizes for our dependencies.

I think if your goal is size reduction, finding lighterweight shims for built-in Node.js modules is a better alternative in this specific case. I worry that maintaining our own Regexp for parsing these URLs is going to cause subtle incompatibilities.

Thanks for the contribution, though! #25 was accepted because it's a super sensible patch that we should've been doing anyway. Cheers!

[fregante]

I feared that would be the case. Thanks for the consideration though 🙂