Add boost-regex

Current contents:
  expat-2.1.0-4.fc18.x86_64.rpm
  fontconfig-2.10.2-2.fc18.x86_64.rpm
  freetype-2.4.10-4.fc18.x86_64.rpm
  zlib-1.2.7-9.fc18.x86_64.rpm
  liberation-fonts-common-1.07.2-12.fc18.noarch.rpm
  liberation-mono-fonts-1.07.2-12.fc18.noarch.rpm
  liberation-sans-fonts-1.07.2-12.fc18.noarch.rpm
  liberation-serif-fonts-1.07.2-12.fc18.noarch.rpm
  libjpeg-turbo-1.2.90-1.fc18.x86_64.rpm
  boost-devel-1.54.0-9.fc20.x86_64.rpm
  boost-filesystem-1.54.0-9.fc20.x86_64.rpm
  boost-regex-1.54.0-9.fc20.x86_64.rpm
  boost-static-1.54.0-9.fc20.x86_64.rpm
  boost-system-1.54.0-9.fc20.x86_64.rpm
  boost-test-1.54.0-9.fc20.x86_64.rpm
  yaml-cpp-0.5.1-1.fc20.x86_64.rpm
  yaml-cpp-devel-0.5.1-1.fc20.x86_64.rpm
  openssl-libs-1.0.1h-4.fc21.x86_64.rpm
  openssl-devel-1.0.1h-5.fc21.x86_64.rpm
  libcom_err-1.42.10-5.fc21.x86_64.rpm
  krb5-devel-1.12.1-14.fc22.x86_64.rpm
  libcom_err-devel-1.42.11-2.fc22.x86_64.rpm
  krb5-libs-1.12.1-9.fc21.x86_64.rpm
  keyutils-libs-1.5.9-4.fc22.x86_64.rpm
  libselinux-2.3-4.fc22.x86_64.rpm
  pcre-8.35-6.fc22.x86_64.rpm
  xz-libs-5.1.2-15alpha.fc22.x86_64.rpm

Signed-off-by: Avi Kivity <avi@cloudius-systems.com>