RUBY-1176 Show full exception in debug logging
RUBY-1176 Better name for supportability metric

If we drop backtraces on a looooooong transaction, call the metric we count
DroppedBacktraces instead of BacktracesBufferFull
Merge pull request #194 from newrelic/RUBY-1176-config-for-xrays

RUBY-1176 Config settings for X-Rays (and Thread Profiler)
Revert "Temporary debugging shim to track down a stubborn BacktraceService worker thread in unit tests"

This reverts commit 71e05a49d17d3bf5826dd89ed753fe51e3bd5d0d.
Merge pull request #196 from newrelic/RUBY-1176-supportability

RUBY-1176 Supportability metrics
Merge pull request #197 from newrelic/RUBY-1176-prune-dead-threads

RUBY-1176 Prune dead threads from buffered backtraces
Merge remote-tracking branch 'origin/RUBY-1176-stop-sessions-by-duration' into dev

Conflicts:
	test/new_relic/agent/commands/xray_session_test.rb
Merge remote-tracking branch 'origin/RUBY-1176-thread-count' into dev

Conflicts:
	test/new_relic/agent/threading/backtrace_service_test.rb
RUBY-1176 Fix XRaySessionCollection unit test to not leave a BacktraceService thread lying around
Implement beta JS agent instrumentation
RUBY-1176 Move is_supported? to BacktraceService
RUBY-1176 Don't start unsupported BacktraceService

Also avoids harvesting when we're not allowed to.
Use NewRelic.json_dump instead of .to_json
Log JS agent functionality only at initialization time
Revert "Pass beacon configuration to JS header generating method"

The config parameter isn't actually needed

This reverts commit c19e97a2ab63e6fd405b832a94d0ff0e03f048ca.
Simplify use_beta_js_agent?
Document new agent configs
RUBY-1176 Empty agent commands stops active x-rays

When X-Ray sessions are finished, we don't get an empty active_xray_sessions
command from the collector--instead the next get_agent_commands is just empty.
When we see that just shut the whole thing down.
Use string keys in js_data hash to make OkJson happy
Guard against NREUM being undefined when adding params