commentrss 6.x-2.0

This release fixes a few small bugs, improves the memory footprint and SQL queries (better performance), the user interface (cleaner forms, slightly more flexible options, better translatability) and improves code quality (better file organization, more phpdocs). Includes forward ported changes to commentrss from 5.x-1.x to 5.x-2.x, including:

• #214958 by Junyor and myself: add context to comment feeds, so people can identify where comments are coming from
• #161150 report by twohills, patch by myself: Add different options for site front page feed exposure, and prevent all site feed from appearing on other pages. Setting backwards compatible.
• Update help text to describe feed features better.
• Moved settings page under 'RSS publishing' setting in admin > content.
• #198151 report by ragaskar, patch by myself: avoid node comment RSS feed from appearing on other pages.
• Removed lots of dead code from node comment feed generation code.
• #189829 reported by zostay, mostly fixed already, but one missing piece: Built in check for comment support on node, so that a node feed will not be accessible at all if the node does not support comments.
• Remove vocabulary feed as vocabulary_list module is not supported for years. Use Views for arbitrary comment feeds.
• Added lots of phpdoc to API functions.
• Align namespace handling in channel feed to core patch suggested at #157709
• Rethink commentrss_format_items() to join on {users} instead of doing a user_load() on all comments handled. This leads to much better performance.
• Better descriptions on settings.
• Also used Drupal 6 features to split the module into pages.inc, admin.inc and the main module file only containing core hook callbacks, minimizing memory footprint.