Update CONTRIBUTORS
Merge #85: Check if GPG end marker exists

Picked up by @manizzle.

"lines.between() does not check if the end marker actually exists, but
later it is assumed the marker exists. This change introduces a check
for the end marker and doesn't decrypt messages in which the end marker
is missing. This is a fix for http://rubyforge.org/pipermail/sup-talk/2010-August/004209.html"

Source:
http://permalink.gmane.org/gmane.mail.sup.devel/641
Grammar :-)
poll.rb: remove some ws bs
Source poll thread safety: lock source polling
move go_idle to ensure
change @polling to Mutex for thread safety
Load libc.so.7 instead of .6 on FreeBSD
Prepare for 0.13.2
Merge branch 'line-0.13-develop' into line-0.13
Bump version to 0.13.2