In this example, 'dmtcp_launch -i 2' was invoked to checkpoint
every 2 seconds.  This plugin causes the application applic.c to delay
the checkpoint that is requested by the coordinator In this example,
the plugin could be omitted.

Note the need to compile with -fPIC the target file that
uses dmtcpDelayCheckpointsLock().
This is needed so that the same binary can used both with and without DMTCP.

This example is sufficient for most application, but more advanced
hooks to DMTCP are also listed in applic.c .
