statpost() refactored to fork-n-wget with individual node logic retained - KE8CGS

[TheCranston]

Description This is an update to app_rpt.c which replaces the libcurl code in the statpost function. It reverts to the old fork-n-wget method from the 1.01 release but retains the 1.02 logic allowing a per node statpost override. This PR fixes a previous PR #76 that didn't glob the arguments for the exec correctly. It also restores the statpost_program part of the rpt struct and replaces the code to read that variable from the config file. There was some little code chunk that didn't sync into my fork about tail and beaconing, I added it back in manually here so you might notice that, but it's not a change...

Checklist

• [X] Pull submitted to correct branch of repository (develop)
• [X] Code compiles correctly
• [NA] Information on how to compile code included
• [NA] Created tests which fail without the change (if possible)
• [X] All tests passing
• [X] Any tests done are included along with their resuts (pass or fail)
• [NA] Extended/created the README / documentation, if necessary
• [NA] Added myself / the copyright holder to the AUTHORS file
• [X] Developers Certificate of Origin (DCO) included

[TheCranston]

Oh and I forgot. I changed the default process scheduling from SCHED_FIFO to SCHED_RR. The round robin scheduler is best when used with a full RT Preempt kernel, which is what is under the hood.