Link to the building doc fixed.
Update release notes for 1.1.2

Added note for LOGBACK-959
Merge pull request #175 from maximesinclair/master

Link to the building doc fixed.
LOGBACK-960 Prevent a possible NPE in SyslogAppenderBase.close() when the SyslogOutputStream is null (due to a host lookup failure for example)
LOGBACK-960 Update release notes
Update release notes: swap NPE with NullPointerException for consistency and fix a couple typos