Change pbkit License from LGPL

[DobaMuffin]

Currently, pbkit is licensed under the LGPL which allows for dynamic linking, but currently it's being statically linked. This does not work for people trying to create closed sourced applications with nxdk. In an attempt to remove any sort of GPL'd code from nxdk, pbkit should be licensed by openxdkman. The only other solutions are to replace pbkit, or find a way to dynamically link it.

I know it was done once in #21 but I'm not sure if we can do it again to change it to something with a little bit more freedom.