Load selected feed after a short timeout

Avoid firing multiple server requests if the user is navigating up/down
the tree list with the keyboard. Instead, wait till the user has stopped
navigating for at least 250ms.
Don't preload audio attachments.
colorPalette: try checking imagesize before invoking GD
Small improvements to Spanish
Merge pull request #224 from Menti/master

Small improvements to Spanish
do no try to pass MS icon files to GD
Merge branch 'master' of github.com:gothfox/Tiny-Tiny-RSS
Merge pull request #226 from mhaley/patches-no-preload

Don't preload audio attachments.
Merge pull request #223 from mhaley/patches-viewfeed-timeout

Load selected feed after a short timeout
Merge pull request #227 from whyparkc/master

Pull request for localization for Korean
feedparser: check if initial xpath query for root element returns anything
fixes "undefined index" notice
Merge pull request #228 from WGH-/installer_undefined_index

fixes "undefined index HTTPS" notice in installer script
add rel=noreferrer to article links
Update messages.po

Typo in translation.
Merge pull request #229 from skibbipl/patch-1

Update messages.po
better root element detection for atom content type xhtml (closes #720)
Add missing hotkey handler
Merge pull request #230 from lotrfan/hotkey_fix

Add missing hotkey action
Remove content when an article is dismissed