Making the method Utils.toText() accept objects

[duckbox]

Led from issue https://github.com/yyx990803/vue/issues/83

[duckbox]

I also added a commit that edits the gruntfile to ease the process of contributing. Instead of running the default grunt process, we establish another command to run the lint and test tasks, thus removing the build task. This avoids the future complications of PRs containing edited dist contents.

[yyx990803]

Hmm the grunt task change isn't really necessary. The casper task requires build to be run first anyways, because it's using dist/vue.js. I have edited the contrib guide to clarify not checking in dist files.

Also let's avoid mixing changes for different purposes in the same PR.

[duckbox]

Yeah, that was a mistake on my part. I forgot that this was still open. I've reverted that commit leaving the original commit as the sole PR.

[yyx990803]

Looking good! My last request: can you make it a single clean commit? (ideally, git reset to the commit where you started, make a single commit, then push -f to your fork.)

[duckbox]

Commit spring cleaned. Apologies again.

[yyx990803]

No need to apologize! Thanks for the great work =)