fix(logging): allow sending an exception to the logger

Several places in the Rails codebase the logger is passed an exception
instead of a string, so we should handle this. This implementation
mimics the output from log_exception when being passed an exception.
Ignore errors loading the New Relic library.
move from hot_bunnies -> march_hare
require raven since we use it here
split out raven and logger adapters for exception reporting
hmm, actually add the adapters
remove stale autoloads
check config.sentry.dns, sentry default to an empty hash
don't crash on someone defining a Rails module
fix raven reporter, it is dsn, not dns, stupid
allow customizing the instrumentation key for inheriting classes
use a class instance variable for the instrumentation_key
log format configuration
refactor logging
do not use eval for log formatting
allow configuring metriks reporter type
fix specs
preserve log formatting for metrics logger reporter
graphite reporter wants config
metrics graphite reporter wants host and port. also, rescue exceptions while setting up the reporter