Compiling as requirejs module and other changes in gruntfile

I remembered that it is possible to have multiple builds, so I just added one more object to the settings of `concat` in the gruntfile. The compiled file for require js is then wrapped with define statement.
Before, uglifying(minifying) was turned off, as it was messing paperjs, but I found out that paper-core uglifies  just fine.
Now we have both requirejs module and the simple one, that should still be compatible with what we have running.

Other changes:
```
Fixated package versions.
Change compile directory to dist/
Compile requirejs and simple version, as well as minified ones
Delete obvious comments in Gruntfile, builds and karma.js
```