Export WriteMergedPackage().
Add gopherjs_http package for serving HTML files with "text/go" scripts.

Uses GopherJS to compile Go code into JavaScript on the fly.
gopherjs_http: Fix issue where non-text/go scripts would interfere.

Add todo tasks.
gopherjs_http: Display compile error in stderr.

Add pipe_util.DividedOutputDir.
gopherjs_http: Don't reference .js.map since it's not yet served.
Add GoPackageRepo.
Add docs and example for GoReduceLinesFromReader.
Stop using a dot-imported CheckError func.
Add support for non-inlined text/go script tags.

Make ProcessHtml public.
Minor code cleanup.
gopherjs_http: Don't shell out, use gopherjslib to compile in-process.

This makes the package go-gettable and does not require gopherjs binary.
It's a step up from shelling out, but step below from using
gopherjs/compiler directly. But that step can be take when there's a
concrete need.
Improve interface of GetPublicIps(), cleanup.
Begin work on fixing golang issue 5551.

Start with latest version of go/format.
Add a failing test case.
Use the parse() of gofmt which preserves comments.
Work on merging parse() of gofmt and go/format, fixing 5551 and 4449.

Tests pass.