syncdir: two portability patches

Hi!

A long while ago, to support OS X and its ".dylib" shared-library =

conventions, I've libtoolized the syncdir build. The patch: =

https://github.com/schmonz/syncdir/commit/4e2e070567910dd2859f2d4c386ea2c=
ad0cdb1c6

Yesterday, I noticed that OS X has deprecated syscall(). I've added a =

dlsym()-based implementation that gets chosen if syscall() gives =

warnings or is not present. The patch: =

https://github.com/schmonz/syncdir/commit/fbf12e83d8906d3236f3f696edbc0a5=
cedf102cd

I'd be happy to hear about better or simpler ways to solve these =

problems and/or to have these patches included in syncdir.

Thanks,

- Amitai