i3-input: restore input focus on exit() (Thanks f8l)

fixes #641
Merge branch 'i3-input-focus'
Merge branch 'master' into next
Also draw right tab border for split containers (Thanks alex)

fixes #696
Merge branch 'fix-tab-border'
Merge branch 'master' into next
Fix scrolling on a tabbed titlebar which contains split cons (Thanks f8l)

fixes #708
Merge branch 'fix-scroll-split'
Merge branch 'master' into next
complete-run: clarify the message about missing ../i3 (Thanks Marcos)
userguide: s/mailclient/mail client/g (Thanks joepd)
hacking-howto: clarify where to send patches to (Thanks Vivien)
i3-dmenu-desktop: don’t add “geany” if “Geany” is already present (Thanks Tai-Lin Chu)
Bugfix: Ignore ConfigureRequests for scratchpad windows (Thanks MeanEYE)

fixes #898
Merge branch 'master' into next
Merge branch 'fix-scratch-confreq'
new-test: add launch_with_config to multi-monitor template
Draw 1px tab separators left/right instead of 2px on the right only

fixes #894
Render tree before destroying X11 containers upon unmap (Thanks Merovius)

When an X11 window is closed (say, urxvt), i3 gets an UnmapNotify event
and destroys (DestroyWindow) the window decorations. Before this commit,
the DestroyWindow call was sent immediately.

This lead to a situation where — due to the DestroyNotify — EnterNotify
events were generated that would cause the focus to be set to the
underlying window.

With this commit, i3 first renders the tree and pushes changes to X11
before calling DestroyWindow. Therefore, the surrounding containers will
take up any space that was freed by the window which was closed and no
EnterNotify will be generated.

fixes #660
Bugfix: Correctly close floating windows (Thanks eeemsi)