process.c: move uname parser to a separate file

* uname.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* process.c (sys_uname): Move to uname.c.
diff --git a/Makefile.am b/Makefile.am
index 9342123..ba5e23a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -90,6 +90,7 @@
 	truncate.c	\
 	umask.c		\
 	umount.c	\
+	uname.c		\
 	util.c		\
 	utime.c		\
 	utimes.c	\