(PUP-1529) Make squelch of parse error specific to resource_type command

Without this fix, all indirect loading of .pp logic will silently fail.
With this fix, only queries via the resource_type command have
parse errors squelched in order to allow search to continue past a
syntax error.
Merge branch 'stable'

Conflicts:
	lib/puppet/indirector/resource_type/parser.rb
(PUP-1529) Make squelch of parse error use context instead of global

This fixes up the earlier fix for 3.4.x where a global variable
was used to control if parse errors should be raised or not.

Now the context system is used instead of a global variable. (It is
still a boolean value since there is no other immediate use for a
strategy that either raises the error or logs the problem).