use GNUInstallDirs for dev files
use third-party sqlite3 if pkg-config reports version 3.8.5 installed
 - not sure of the actual incompatibility, but HHVM fails to initialize the central repository with sqlite3 version 3.8.5
specify ssl cipher list for curl with OpenSSL only
Merge branch 'HHVM-3.2' of github.com:johnnywalker/hhvm into HHVM-3.2