Better defaults for web frameworks

[davegurnell]

It would be useful to provide quick setup options for the popular web frameworks, probably implemented as separate sets of settings in each plugin.

For example, in a Lift project you might have a build.sbt that looks like this:

seq(jsSettingsForLift : _*)

and in Spray you might have:

seq(jsSettingsForSpray : _*)

See #42 for a more complete discussion of Lift.

Another idea: quick addition of vendor directories for JS/Less:

seq(jsSettingsForLift : _*)

seq(jsSettingsAddVendorDirectory("vendor") : _*)

Note: check sbt-bower, integrate with its defaults.

[mdedetrich]

If you are wondering, I have forked sbt-bower and vastly improved it, you can see it here https://github.com/mdedetrich/sbt-bower