jasmine.install - explicitly install top-level methods.

- jasmine.install(target) adds the top-level jasmine methods to the target object.  
- auto-detect browser-mode and install on window.  
- auto-detect commonjs mode and install on module.exports.  
- top-level methods are now tightly scoped.

    jasmine.install(global);

I'm doing this based on the jshint and node_suite functionality that I've previously submitted pull requests for (they're necessary in order to get this right).  So when I do a pull request for the jasmine.install stuff, it pulls all those commits along too since those pull requests haven't been merged into jasmine master.

So if this is pull request is accepted, is makes the other two irrelevant.  Just to be clear.