Small changes to falco engine/config wrt new cmdline option parsing

For the most part, replacing getopt() with cxxopts + falco application
had no effect on falco engine/config interfaces. However, there were a
few places where it was wasier to change the interface than add
middleware code that transformed from, for example, vectors to lists.

This commit has those changes.

Signed-off-by: Mark Stemm <mark.stemm@gmail.com>

userspace/falco/configuration.cpp

@@ -51,7 +51,7 @@ falco_configuration::~falco_configuration()
 	}
 }
 
-void falco_configuration::init(string conf_filename, list<string> &cmdline_options)
+void falco_configuration::init(string conf_filename, const vector<string> &cmdline_options)
 {
 	string m_config_file = conf_filename;
 	m_config = new yaml_configuration();
@@ -390,7 +390,7 @@ static bool split(const string &str, char delim, pair<string, string> &parts)
 	return true;
 }
 
-void falco_configuration::init_cmdline_options(list<string> &cmdline_options)
+void falco_configuration::init_cmdline_options(const vector<string> &cmdline_options)
 {
 	for(const string &option : cmdline_options)
 	{

userspace/falco/configuration.h

@@ -216,8 +216,8 @@ class falco_configuration
 	falco_configuration();
 	virtual ~falco_configuration();
 
-	void init(std::string conf_filename, std::list<std::string>& cmdline_options);
-	void init(std::list<std::string>& cmdline_options);
+	void init(std::string conf_filename, const std::vector<std::string>& cmdline_options);
+	void init(const std::vector<std::string>& cmdline_options);
 
 	static void read_rules_file_directory(const string& path, list<string>& rules_filenames);
 
@@ -266,7 +266,7 @@ class falco_configuration
 	std::vector<plugin_config> m_plugins;
 
 private:
-	void init_cmdline_options(std::list<std::string>& cmdline_options);
+	void init_cmdline_options(const std::vector<std::string>& cmdline_options);
 
 	/**
 	 * Given a <key>=<value> specifier, set the appropriate option