bump NSLogger

 Submodule changes to be committed:

 * NSLogger a4dac7a...628f3e0 (9):
   > Merge pull request #95 from collections/master
   > Restore previous fixes lost after merge
   > Merge branch 'master' of github.com:fpillet/NSLogger
   > Removed unused variables
   > Updated test code and test project to recent Xcode settings
   > Shield against console messages hiding format strings
   > Fixed longstanding issue: store unlimited number of messages in logQueue
   > Rewrote the connection / reconnection logic for better reliability
   > Update README.markdown
re-add building on the mac

+ disable -Werror for now as NSLogger has some
deprecation warnings