Fix the extension API compatibility check and remove non-core extensions from core packages.
Remove examples.

Now that the examples are present in the go-gl/examples repo there is no
need to have a redundant copy in the glow repo.
Merge pull request #29 from errcw/rm-examples

Remove examples.

Now that the examples are present in the go-gl/examples repo there is no
need to have a redundant copy in the glow repo.

Fixes #22.
Merge branch 'master' into core-extensions
Merge pull request #28 from errcw/core-extensions

Fix core extensions.

Fixes #24.
Update the spec XML and prebuilt packages.

Fix two blocking issues. One, fix the permissions assigned to the
REVISION file upon creation. Two, fix the handling of statically sized
array parameters.