BURP 1.4.16

Update the BURP version
Fix some directory issues (now use /usr/local/sbin instead of /usr/local/bin)
Note: version 1.4.16 fix a compilation error on OS X, see https://github.com/grke/burp/issues/198
Sorry for the indent, I don't know how that happened.
For the sbin, I thought it was necessary after reading this comment:
https://github.com/Homebrew/homebrew/commit/619c35abb5ebf30c714971d7b8aef0c64b3945cf#commitcomment-5714320