Doc: use standard wording in \brief commands

QDoc does some magic with the \class and \namespaces
and \brief commands, so the following wording must be used:
"The xxx class yyy ..."

Change-Id: Id231f30e8464898b776888d5423523de404aae34
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/cpaster/cpasterplugin.cpp

@@ -69,8 +69,8 @@ namespace CodePaster {
 
 /*!
    \class CodePaster::CodePasterService
-   \brief Service registered with PluginManager providing CodePaster
-          post() functionality.
+   \brief The CodePasterService class is a service registered with PluginManager
+   that provides CodePaster \c post() functionality.
 
    \sa ExtensionSystem::PluginManager::getObjectByClassName, ExtensionSystem::invoke
    \sa VcsBase::VcsBaseEditorWidget