Multiple trust stores

This patch updates PluginCertInfo to support use of multiple trust stores and EV validation using multiple CA roots.

Trust stores are expected to be available as files with multiple certs in PEM-format and the files when the plugin is loaded. For each Trust Store, sslyze creates a separate SSL_ctx and loads the Trust Store before verifying the trust chain and the result for each of the Trust Stores are reported separately.

The EV validation files are no longer a Python list that is included into the code, but instead JSON-files that contains OIDs, fingerprints and certinfo. Currently only OIDs are used by the EV-validation. Validation and result is reported separately for each file loaded.

This patch also adds a common verbosity flag to sslyze to allow different levels of verbosity/debug information to be presented to the user.