Docs[mqbcfg]: Complete conversion of mqbcfg documentation from BDE st…

…yle to Doxygen style (#575)

* Convert mqbcfg documentation to Doxygen format

This patch makes two changes:

1. First, it converts the BDE-style component documentation into Doxygen
   `@file` documentation.

2. Next, it converts stray BDE-style documentation that was not
   automatically converted to Doxygen format when we open-sourced.

This patch continues the work from commit d47304d.

Signed-off-by: Patrick M. Niedzielski <[email protected]>

* Migrate mqbcfg docs directory into a Doxygen file

This patch removes the old `doc/*.txt` file and migrates some
information in it into a file Doxygen can read.  The information not
migrated is:

  1. the table of contents for this package, which can be
     auto-generated from each component’s documentation, and

  2. the hierarchical synopsis.

This continues the changes made in commit 8c8af57.

Signed-off-by: Patrick M. Niedzielski <[email protected]>

---------

Signed-off-by: Patrick M. Niedzielski <[email protected]>

src/groups/mqb/mqbcfg/README.dox

@@ -0,0 +1,9 @@
+/**
+@dir mqbcfg
+
+@brief The `MQBCFG` (BlazingMQ Broker Config) package provide broker
+configuration schema and message component.
+
+This package provides the schema of the configuration used by the broker, as
+well as the generated corresponding messages component.
+*/

src/groups/mqb/mqbcfg/mqbcfg_brokerconfig.h

@@ -17,14 +17,13 @@
 #ifndef INCLUDED_MQBCFG_BROKERCONFIG
 #define INCLUDED_MQBCFG_BROKERCONFIG
 
-//@PURPOSE: Provide global access to broker configuration.
-//
-//@CLASSES:
-//  mqbcfg::BrokerConfig: mechanism to set and get the broker configuration.
-//
-//@DESCRIPTION: This component defines a mechanism, 'mqbcfg::BrokerConfig',
-// that provides a safe way of setting and getting a pointer to the global
-// broker configuration.
+/// @file mqbcfg_brokerconfig.h
+///
+/// @brief Provide global access to broker configuration.
+///
+/// This component defines a mechanism, @bbref{mqbcfg::BrokerConfig}, that
+/// provides a safe way of setting and getting a pointer to the global broker
+/// configuration.
 
 // BDE
 #include <bsls_cpp11.h>
@@ -39,6 +38,7 @@ class AppConfig;
 // struct BrokerConfig
 // ===================
 
+/// Mechanism to set and get the broker configuration.
 struct BrokerConfig {
     // NOT IMPLEMENTED
     BrokerConfig() BSLS_CPP11_DELETED;

src/groups/mqb/mqbcfg/mqbcfg_tcpinterfaceconfigvalidator.h

@@ -24,21 +24,17 @@ BSLS_IDENT_PRAGMA_ONCE
 
 #include <ball_log.h>
 
-/// PURPOSE: This component provdies a class to validate TcpInterfaceConfig
-/// settings in the broker config.
+/// @file mqbcfg_tcpinterfaceconfigvalidator.h
 ///
-/// CLASSES:
-///  mqbcfg::TcpInterfaceConfigValidator: A predicate object that validates the
-///  TCP interfaces in the broker config
-///
-/// DESCRIPTION:
+/// @brief This component provdies a class to validate `TcpInterfaceConfig`
+///        settings in the broker config.
 
 namespace BloombergLP {
 namespace mqbcfg {
 
-/// @brief This class is a functor that validates the
-/// `appConfig/networkInterfaces/tcpInterface/listeners` property of the broker
-/// config.
+/// This class is a predicate object that validates the
+/// `appConfig`/`networkInterfaces`/`tcpInterface`/`listeners` property of the
+/// broker config.
 class TcpInterfaceConfigValidator {
   private:
     // PRIVATE STATIC FUNCTIONS
@@ -50,6 +46,7 @@ class TcpInterfaceConfigValidator {
 
   public:
     // TYPES
+
     /// Codes to indicate the reason for a validation failure.
     enum ErrorCode {
         /// Indicates a config is valid. Guaranteed to equal zero.
@@ -64,7 +61,7 @@ class TcpInterfaceConfigValidator {
 
     // ACCESSORS
 
-    /// @brief Validate the TCP interface configuration.
+    /// Validate the TCP interface configuration.
     ///
     /// The TCP interface configuration is invalid unless:
     /// 1. The names of each network interface is unique