#631 Auto Scale Groups Filtering

Auto Scale Groups Filtering
skip filter if values are empty (TheWeatherCompany/grid-api#509)
#631 auto scaling group filtering. backwards compatibility is done for tests
Fixes for upstream pull request.

Fixes #1, #4, and #7 discussed in
https://github.com/greese/dasein-cloud-aws/pull/128.
Changed vlan/subnet conditional to use subnetId for launching instances.
Renamed ServerCertificate -> SSLCertificate (#670)
Implemented AWS working with SSL certificates, not tested yet (#670)