Fact-type specific host's last_compile time
The last_compile time is right now global. Which means:
1. importing facts of one type would prevent importing facts of another type (see http://projects.theforeman.org/issues/15524 for specific case), due to https://github.com/theforeman/foreman/blob/1.11.3/app/models/host/base.rb#L142
2. the time of the fact might be wrong https://github.com/theforeman/foreman/blob/1.11.3/app/helpers/fact_values_helper.rb#L3, as the last_compile time is used
to show time of the fact.
We should probably make the last_compile a type-specific type so that they don't interfere with each other.