(PUP-2995) Move custom oid mapping file management to application/master.rb

* As suggested by @adrienthebo, custom oid management was moved to application/*.
* Custom oid management is only involved if `trusted_node_data` is activated.
(PUP-2995) Change custom OID format and apply code advices.

* As suggested by @ffrank, custom OID file format was changed to use Hash structure.
* Apply code modifications suggested by @ferventcoder.
Merge branch 'external_trusted_oid_map' of github.com:ccin2p3/puppet into ccin2p3-external_trusted_oid_map
(maint) Change ParseError to Puppet::Error

The ParseError issued in oids.rb did not make use of ParseError's
ability to report file, position etc. Using the lower level
Puppet::Error instead which accepts message and optional original error.
Merge branch 'ccin2p3-external_trusted_oid_map'