look for hand-compiled image magick
Use PATH_SUFFIXES for imagemagick

This is a better solution than the hack I added before
include <sys/time.h>

ubuntu 10.04 won't compile without this saying

    /home/ptarjan/dev/hhvm/hphp/runtime/base/ssl-socket.cpp: In member function ‘bool HPHP::SSLSocket::enableCrypto(bool)’:
    /home/ptarjan/dev/hhvm/hphp/runtime/base/ssl-socket.cpp:574:25: error: aggregate ‘HPHP::SSLSocket::enableCrypto(bool)::timezone tz’ has incomplete type and cannot be defined
             struct timezone tz;
                             ^
    /home/ptarjan/dev/hhvm/hphp/runtime/base/ssl-socket.cpp:576:31: error: ‘gettimeofday’ was not declared in this scope
             gettimeofday(&tvs, &tz);
                                   ^
    make[2]: *** [hphp/runtime/CMakeFiles/hphp_runtime_static.dir/base/ssl-socket.cpp.o] Error 1

Reviewed By: @fredemmott

Differential Revision: D1232313