Utils: Use ~/.config if $XDG_CONFIG_HOME is unset

Instead of checking $XDG_CONFIG_HOME manually, just use glib's
get_user_config_dir, but still check if ~/.corebird exists and if it
does, use that.
ui: Remove label test of hidden GtkLabels
ScrollWidget: remove old debugging output
MentionsTimeline: Don't show everything twice

This was happening whenever the user opened the page for the very first
time via the keyboard shortcut.
TweetListEntry: Reset the retweet_button at the correct position

Which is on focus-out of the entire row, not the reply_entry.
TweetListEntry: Don't hide the quick reply stuff...

... on focus-out of the reply_entry. Funnily, focusing the reply_button
and pressing return just activated the row, not the button.
TweetListEntry: Fix the rt_label once more

... just kill ImageLabel, it's causing more trouble that it's supposed
to solve.
Remove ImageLabel
MainWindow: Some whitespace fixes
schema: Fix typo
TweetInfoPage: Don't wrongly show the location icon
CMakeLists: Silence the C compiler a little more
MainWindow: Fix scroll position 'saving'

Ok. If we set the 'active' property of the tool button of a page, the
clicked signal gets fired(which is reasonable). BUT we call switch_page
in out clicked handler. That is generally correct(for scrolling up on
second click, i.e. double_open behavior), but not if we are
already switching the page.
Introduce a window-local page_switch_lock to 'fix' this.
ScrollWidget: Refactor scroll_up_next

...we now just update the transition end values if we already connected
to size_allocate.
Merge branch 'master' into lists

Conflicts:
	CMakeLists.txt
	src/MainWindow.vala
UserListDialog: Fix valac warning
UI: Add GtkAdjustments to prevent startup criticals

Finally.
UserListDialog: Implement adding/removing users from a list
Add a way to hide the sidebar