changes, as per glasser's code review
check to make sure package names don't start with a dot
better error message
even better wording
even better wording
'meteor create --package foo' in app DTRT

It puts the package in $APPROOT/packages/foo instead of ./foo.
Improve package name/version parsing errors

We now throw more specific errors, consistent between both tools and
package-version-parser (copy-and-pasted code, sadly, but we really do
have to make this check before uniload-from-checkout).
fix buildmessage errors within onUse/onTest

Adding buildmessage.markBoundary ensures that we don't display a stack
containing the call stack in the tool above this point.
Use buildmessage better in api.use, etc

Provide good messages when you provide invalid things to api.use and
api.imply.

Provide better message when you provide invalid things to
api.versionsFrom.

Drop "notInitialized" hack from catalog: now that we load things in
order, it's not necessary.  (This means life will break if you use
api.versionsFrom in a uniloaded package. So don't do that.)
stop uniload packages from using versionsFrom

They don't need to and it won't work.
De-dup package name/constraint parsing code

Now we can all any of them from even before uniload is ready in the tool

I <3 symlinks
fix tests that tested lies!
great, now we can use parseConstraint
fix old bundler test failure
Make unknown package failure better

We throw a better (eg, constraintSolverError-tagged) "package not found"
at the appropriate spot later.
Remove distracting #web.browser from CS errors

You can get them back with $METEOR_SHOW_UNIBUILDS.
Merge branch 'release-0.9.0' into devel