Ignore SIGPIPE in the main body of the dx function dispatcher
Ignore SIGPIPE in err_exit()
Merge pull request #47 from dnanexus/PTFM-9757-ignore-SIGPIPE

Ignore SIGPIPE in the main body of the dx function dispatcher
Set Java source encoding explicitly.

This fixes the following warning when building:

  [WARNING] Using platform encoding (UTF-8 actually) to copy filtered
  resources, i.e. build is platform dependent!
Add DXJSON.ArrayBuilder (helper for making JSON arrays).
Changelog and dxR version update for v0.73.0