update for modern TTRSS

[mtfurlan]

This is a set of updates to work with current ttrss.

• Used public functions instead of plugin functions like api_resize does
  • https://community.tt-rss.org/t/question-about-csrf-in-plugin-handler/4939/2
• switch from HOOK_RENDER_ARTICLE_CDM to HOOK_ARTICLE_FILTER
  • I'm not really sure when HOOK_RENDER_ARTICLE_CDM gets called, but api_resize seems to suggest we would need to handle a few more cases
  • HOOK_ARTICLE_FILTER gets called when the article is first processed
• copied pieces processArticle function from api_resize because I thought it was easier to read
• Updated from Db::get to db::pdo
• Removed PhCURL because it was doing something weird and I didn't want to debug
• Stole the settings save code from somewhere else because Ajax.request didn't work anymore
• put a newline between function and open { because some functions had that and I like that style better

This closes #5