CMake: install to correct lib dir (#93)
CMake: install to correct lib dir (#93)

64-bit libraries should be installed in /usr/lib64, not in /usr/lib/
Make the destination lib dir configurable.

Commit e13e72e17692f5dc0036460d734c637b563f3ac7 removed
include(GNUInstallDirs) and ${CMAKE_INSTALL_LIBDIR} which broke
installing on 64-bit systems.

Signed-off-by: Jason Zaman <68c46a606457643eab92053c1c05574abb26f861@perfinion.com>
google/double-conversion,google/double-conversion,floitsch/double-conversion,floitsch/double-conversion,google/double-conversion