Re-enable XML-based history plugin, fix history file saving
Review Request #130154 - Created June 10, 2017 and submitted
The history plugin port was not completed, so it is disabled. This patch re-enables it, fixes it's building failures and fixes not saving the history file when the directory doesn't exist.
Pull from here: https://github.com/paulolieuthier/kopete/commits/fix-history-plugin
Tested last messages appearance on reopening a chat window, using Jabber and Test Protocol.
Laurent, Pali, if I commit this as it is, then https://git.reviewboard.kde.org/r/130161/ (which ports all debugging statements to categorized logging) but splitting out https://github.com/paulolieuthier/kopete/commit/6a49f82775f3ebc164085874942a519d575b576e before, would it be acceptable?