+ Add system timestamps to lua read() and new lua read_line() per global options

+ Add missing timestamp-format epoch
+ Update send_ to use fsync and tcdrain like normal tty_sync does
+ Rework read_line to save partial line at timeout
+ Simplified read_line to reduce cyclomatic complexity

+ renamed example files read.lua and read_line.lua
+ moved #define READ_LINE_SIZE to top of file
+ renamed g_linebuf to linebuf, and moved it into read_line as a static variable

src/options.c

@@ -19,6 +19,8 @@
  * 02110-1301, USA.
  */
 
+#define _GNU_SOURCE // To access vasprintf
+
 #include <assert.h>
 #include <regex.h>
 #include <getopt.h>