- moved "nimbus/api" to "wrappers"
- renamed files
- replaced the build scripts with Makefile targets
- set the rpath relative to the test binary's location so it can look
for libnimbus.so there at runtime
- libnimbus.so.0 required on Linux, apparently
- compiled all the Nimbus code with `--app:lib`, not just one file (this
required skipping a proc in "nimbus/config.nim" because it uses an API
that's unavailable in libraries)
- removed static linking from the Go wrapper. It doesn't make sense at a
global level, when using a shared Nimbus library. To selectively link
static libraries, we should probably be specifying them as *.a. I did
build a static libnimbus.a, as a test, but it insisted on dlopen-ing a
shared version of itself which looked too ugly to continue.