message: Update copyright year
  Bump version to 0.15.2
diff: @@ -2,10 +2,10 @@ dnl require autoconf 2.60 (AS_ECHO/AS_ECHO_N)
  AC_PREREQ([2.60])
  define(_CLIENT_VERSION_MAJOR, 0)
  define(_CLIENT_VERSION_MINOR, 15)
  -define(_CLIENT_VERSION_REVISION, 1)
  +define(_CLIENT_VERSION_REVISION, 2)
  define(_CLIENT_VERSION_BUILD, 0)
  define(_CLIENT_VERSION_IS_RELEASE, true)
  -define(_COPYRIGHT_YEAR, 2017)
  +define(_COPYRIGHT_YEAR, 2018)
  define(_COPYRIGHT_HOLDERS,[The %s developers])
  define(_COPYRIGHT_HOLDERS_SUBSTITUTION,[[Qtum Core]])
  AC_INIT([Qtum Core],[_CLIENT_VERSION_MAJOR._CLIENT_VERSION_MINOR._CLIENT_VERSION_REVISION],[https://github.com/qtumproject/qtum/issues],[qtum],[https://qtum.org/])
  