New approach for reload safety belt testing.

Mutating global state in tests is still not a good idea. (Specifically,
in the previous version of the test, changing the value of
`WebAppInternals.inlineScriptsAllowed()` could mess with other
client-side tests that depend on it being one way or another -- of which
there are currently probably none, but there could be in theory.)

Instead, export the exact things we want to test (boilerplate HTML
generation and the static file handler). Now we are still mutating the
global `inlineScriptsAllowed()` state, but we don't yield before setting
it back to what it was.

Also simplify the reload-safetybelt test: instead of sending an HTTP
request, just check that the script gets adding to
`WebAppInternals.additionalStaticJs`.
Wrap webapp test code in _noYieldsAllowed.
Support HTMLification

Breaks webapp_server pretty hard
Rename serveStaticFiles to staticFilesMiddleware
Merge branch 'reload-safetybelt-package' into devel
when uploading tarballs, check for errors

and throw something that looks better than [Object Object]
Introduce OLDSTYLE flag to not break webapp

Making webapp_server work requires #if and #each that work with toHTML.  Don’t want to have to write that code just to be able to run client code again.
self-test now passes
Implement lookup, more builtins

Move lookup to templates, not views!
Fix #with; set current view on autorun
Capitalize something
Tweaks to view kinds
Correctly null out template{Content,Else}Block
Progress on #each
Cleanup; Templates have a prototype
Restore optionality of loginWithPassword/changePassword callbacks.

Fixes a regression in 0.8.2.

Fixes #2255.
ReactiveVar doc comments
Update BUNDLE_VERSION note in meteor script
Port UI.getElementData
Observe-sequence package recognizes different cursors by checking the interface
of observe and fetch.

Before it checked that the cursor is an instance of Minimongo.Cursor.