fix proxygen build on OSX
add a pthread time lock shim
add system-agnostic time functions
implement __GNUC_PREREQ/__GLIBC_PREREQ on systems that don't have it
Use https:// instead of git:// for submodules
[1/2] fix thrift build on OSX
osx does not define these ipv6 fields
don't build unnecessary fastlz objects

These 2 stand-alone utilities are not used by HHVM and they define a
main() that may cause certain linkers to complain about duplicate
symbols:

Linking CXX executable hhvm
duplicate symbol _main in:
    CMakeFiles/hhvm.dir/main.cpp.o
    ../../third-party/fastlz/libfastlz.a(6unpack.c.o)
duplicate symbol _usage in:
    ../../third-party/fastlz/libfastlz.a(6unpack.c.o)
    ../../third-party/fastlz/libfastlz.a(6pack.c.o)
duplicate symbol _detect_magic in:
    ../../third-party/fastlz/libfastlz.a(6unpack.c.o)
    ../../third-party/fastlz/libfastlz.a(6pack.c.o)
duplicate symbol _main in:
    CMakeFiles/hhvm.dir/main.cpp.o
    ../../third-party/fastlz/libfastlz.a(6pack.c.o)
ld: 4 duplicate symbols for architecture x86_64
update folly commit hash
Merge pull request #9 from danslo/proxygen-fastcgi-osx

fix proxygen build on OSX
Merge pull request #10 from danslo/thrift-fastcgi-osx

[1/2] fix thrift build on OSX
Merge pull request #11 from danslo/thrift-fastcgi-osx2

[2/2] fix thrift build on OSX
Merge pull request #13 from danslo/fastlz-duplicate-symbols

don't build unnecessary fastlz objects
change reference from gettime to clock_gettime

This was incorrectly copied from HHVM's timer.cpp. There is no such
function as gettiem in the C library.
Merge pull request #14 from danslo/gettime

change reference from gettime to clock_gettime
Update folly remote