process.c: move get*uid and set*uid parsers to a separate file

* uid.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* process.c (sys_getuid, sys_setfsuid, sys_setuid, sys_getresuid,
sys_setreuid, sys_setresuid): Move to uid.c.
diff --git a/Makefile.am b/Makefile.am
index 52f7f46..c4f3326 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -90,6 +90,7 @@
 	term.c		\
 	time.c		\
 	truncate.c	\
+	uid.c		\
 	umask.c		\
 	umount.c	\
 	uname.c		\