Factor out almost all fs. and path. calls in the tool

This will be useful when we want to be smart with windows file paths later
Also, all of the file calls are asynchronous with fibers now, which comes with
many benefits.

This is a combination of 23 commits. Original messages:
Wrap a large number of fs calls inside files.*

Convert a few more fs calls to files.*

More moving fs.* to files

Implement read/write streams and open/read/close

Get rid of fs from auth.js

Remove fs and unused imports from catalog-local and catalog-remote

Remove unused imports from catalog.js

Replace a whole lot of fs calls

Fix error

Migrate a lot more fs. calls to files.

Add a temporary symlink method

Convert old test to files.*

Use files.pathX instead of path.x everywhere

Replace path.x to files.pathX in tests

Small fixes to files.js and one rename

Make cleanup run in a fiber

Make wrapping functions take function name in case we need it

Add some timeouts and stuff to HCP tests

wrapFsFunc also makes a sync version of the function

Sometimes you just don't want to yield!

Make sure JsImage readFromDisk doesn't yield

Remove unused imports from npm test

Change order of test now that some things don't yield

Fix missing files import, and add a debug error printout
Replace rm_recursive with a modified rimraf
Reimplement files.rename with the retry logic for Windows
Use isopack metadata to find existing builds
Factor out making latest meteor "symlink"
Factor out the symlink dance into _saveIsopack
Factor out symlinking to meteor tool in selftest and tropohouse
Some reorganization of files.js
Add function to call Npm, special case for Windows

Conflicts:
	tools/meteor-npm.js
Lookup npm.cmd instead of npm on Windows
Replace process.env.HOME with files.getHomeDir()

Conflicts:
	tools/commands-cordova.js
	tools/config.js
	tools/files.js
	tools/selftest.js
	tools/warehouse.js
Make carriage return portable

In unix we can just use '\r';
In Windows the easiest way is to print a lot of '\b';
Remove extra console.log
Throw an error when we can't build an arch

Instead of failing silently
Add installer heavily based on Stephan Darnell's
Add mongo fix
Send correct kill signal
Add 64 bit arch for Windows
Add windows x64 arch to the list of accepted args

for meteor admin get-machine.
Make tool able to do oauth against new and old OAuth configurations

Previously, the tool was hard-coded to use "?close" at the end of
redirect uris when it did OAuth flows with e.g. package servers or build
farms. Now, we use the same logic that the server uses to compute its
redirect uri: we add "?close" if a loginStyle option is present in the
configuration.