Don't create new Threads while using EventMachine.

Use EM.defer instead in order to use EventMachines internal work queue
and thread pool. This change was made in the hope of fixing the Ruby
interpreter blowup on CI and occasionally on development machines.
remove old pkg directories
Splitting migrations into two files, make tests pass.
Always set the Siger.logger upon creation

There is currently a bug in the Sigar Ruby C extension whereupon the
logger attribute of the Sigar class is marked for GC cleanup even if it
was never set. There is a GitHub issue for this bug here:

  https://github.com/hyperic/sigar/issues/28
[finishes #46676063] Moving AWS create commands to migrations
Migrate a specific version, adding individual aws create commands back.

Since the external specs depend on those individual commands, I've
added them back through the usage of single migration commands. That improves
the testing time a lot, because every single test does not need to recreate
all aws stuff (mainly RDS).