This commit:
1. Restores --tls_plugin as a way to provide the path to the TLS plugin when running in simulation.
2. Removes the TLS Plugin as being required for 5% of tests.
3. Standardizes on 'sslEnabled' as a variable name.
And is a fix/improvement upon commit f7733d1b.
(1) previously didn't work, because we would create multiple new TLSOptions
instances and run init_plugin multiple times. Only the first call would use
the argument specified on the command line. To fix this, the TLSOptions
derived from the command line is threaded through all the simulation code that
needs it.
(2) was an oversight in f7733d1b, which didn't actually make "should we be TLS"
dependant on if the TLS plugin was available or not.
(3) is just nice for trying to grep around in the codebase.
It appears that explicit calls to TLS-related things had snuck in over time,
which meant that simulation runs that weren't even configured to use SSL still
wanted and required the TLS plugin.
This commit instead threads through the understanding of if any TLS-related
options were provided, and if not, then don't call anything TLS-related so that
we don't require the TLS plugin.
Hopefully this makes life easier for the opensource folk. :)