Allow for specifying imports at beginning of templates

[benmccann]

Right now you have to specify imports after the template declaration:

@(user: com.example.User)
@import com.example.User
Hello @user.getName()

This seems odd because it's not how Java/Scala classes work and also because it results in much more typing than the alternative:

@import com.example.User
@(user: User)
Hello @user.getName()

I took a stab at implementing this here: playframework/playframework#1661

[benmccann]

@pvlugter several people were asking for this awhile back (@siasia @diwa and others). this was something that had always frustrated me as well, so I took a stab at implementing it. the pull request languished for awhile because the core devs understandably didn't want to be editing the templates while trying to split them out into a separate project. it looks like twirl is alive and well now so this might be a good time to revisit. unfortunately, i'm absolutely slammed at work right now and am not going to have much of a chance to make any updates to the pull request. i think it should be relatively close. do you think you'd be able to run with it from here?

[pvlugter]

@benmccann sure, no problem.

[benmccann]

that's awesome. thanks so much!

[benmccann]

that's awesome. thank you!!