Sync existing sources with glibc-2.15

Only a few trivial changes since 2.13.
Import file types from glibc-2.15.

Many of these such as networks, protocols, etc. make a lot of sense for
this module since they are usually never customized and thus have little
need to actually be in /etc all the time.
Compile all new file types, update CFLAGS

Fairly simple compile fixes:
 - Get better warnings (-std=gnu99 -Wall)
 - Add a few more includes and stub macros to compat.h
 - Fix symbol names in file-hosts.c
 - Don't export the function defined by LINE_PARSER in files-parse.c