GLib <2.30 compat header added to serialize.c
Merge pull request #12 from jaromil/older-glib-compat2

GLib <2.30 compat header added to serialize.c
Fix O_LARGEFILE build breakage on OSX

Fixes #13
Merge branch 'master' of github.com:jgarzik/picocoin
Merge branch 'master' of git://github.com/jgarzik/picocoin