Fix right aligned statusbar item redrawing

Fixes Github issue #97 https://github.com/irssi/irssi/issues/97

Fix proposed by ailin-nemui, built and tested on Debian Jessie using
0.8.15 source, tested by GeertHauwaerts as well.
Merge pull request #109 from cpbills/master

Fix right aligned statusbar item redrawing
Add bounds check to array access in terminfo driver.

this fixes a crash due to illegal memory access that can occur if
something is printed to the screen on the "terminal resized"
handler. It is not clear to me whether this race condition can be
triggered by external incoming messages, but it might be better safe
than sorry.
Merge pull request #123 from ailin-nemui/terminfo-scroll-check-bounds

Add bounds check to array access in terminfo driver.
Add the signal for printtext_after that was missed in the original commit.

Now properly sends "gui print text after finished" signal when using
the printtext_after API that was fixed after 0.8.16
Merge pull request #134 from ailin-nemui/missing-printtext-after-signal

Add the signal for printtext_after that was missed in the original commit.
Prepare for irssi 0.8.17-rc2.
Head is now 0.8.17-head.