[oe] [meta-networking][PATCH v2] chrony: Versatile implementation of NTP

[Henry Hallam]

Patch version 2:
- No longer hard-coding paths  
- Fix missing build dependencies, depending on PACKAGECONFIG features 
- Split off chronyc into separate output package
- Default config points to openembedded.pool.ntp.org rather than
  pool.ntp.org (which should never be shipped as a default)

I have applied for the above NTP pool vendor zone per
http://www.pool.ntp.org/en/vendors.html#vendor-zone

Thanks, Henry