some improvement to appdata summaries
fix some missing whitespace, and standardise the placement of the whitespace. thanks to Thomas Bellmann.
use standard hyphen-less "Claws Mail" in user-facing strings. Thanks to Thomas Bellmann.
fix bug 3306, 'HTML tag </b> is not always rendered in error dialog'
RSSyl: fix markup escaping in one more alertpanel_error in rssyl_update_feed()
Use gnutls_priority override also for POP3 connections.