Build for scala 2.11

Hi,

  I've build widgets module for Scala 2.11. Could you please integrate? In addition I removed unnecessary dependencies and upgrade sbt, log4j and logback to the latest versions.
There is no build of modules for scala 2.11 and lift 2.5. if you are using lift 2.5, you can only use up to scala 2.10.x

But, when we build the modules for lift 3.0, what we do is some sbt magic:

```
sbt> set liftVersion := "3.0-M1"  //this changes the lift version the module is going to be build for, during this sbt session
sbt> ++2.11.1 //because lift 3.0 will only be build for scala 2.11.x starting with lift 3.0-M2
sbt> publish // so here we publish the module for lift 3.0 using scala 2.11.1

```
without having to modify the build.sbt file.

So, if you are building your own module, you can follow more or less these steps too (feel free to start a thread on the mailing list if you would like more help or clarify what I'm talking about)

Thanks for the changes and the PR !