Make ValidatorFactory available on Bootstrap

`ValidatorFactory` is used to obtain `Validator` instances in several
places (including configuration validation).

Instead of using a singleton instance, let's make this available on
`Bootstrap`, so that validation may be customised (e.g. by `Bundle`s).
Add support for performing validation of individual elements of a collection (#470)
Adding a test to confirm behavior of a nested list
config: Add ability to override config settings that are in arrays and maps
config: Add ability to override config settings that are in arrays and maps
Merge branch 'master' of github.com:cmicali/dropwizard

Conflicts:
	dropwizard-configuration/src/main/java/io/dropwizard/configuration/ConfigurationFactory.java
	dropwizard-configuration/src/test/java/io/dropwizard/configuration/ConfigurationFactoryTest.java
	dropwizard-configuration/src/test/resources/factory-test-valid.yml
docs: Updated docs to include notes on config override enhancements
Removing maximum limit on archivedFileCount for file logging.
Merge pull request #474 from reines/remove_max_archivedfilecount

Removing maximum limit on archivedFileCount for file logging.
Use current timestamp for request log events.

Fixes #477.
Use next available tcp port when starting server
Merge ../dropwizard
Merge pull request #478 from kschjeld/master

Use next available tcp port when starting server in unit tests, not default port
Update core.rst

Configuration example needs to provide property naming to match the yaml example.
Merge pull request #479 from christophercurrie/patch-1

Update core.rst
Merge pull request #456 from cmicali/master

Add ability to override config settings that are in arrays and maps
Fixed org.eclipse.jetty.server.handler.AbstractHandler warnings
Merge pull request #468 from dropwizard/feature/bootstrap-validator-factory

Make ValidatorFactory available on Bootstrap
Merge pull request #482 from jhalterman/master

Fixed org.eclipse.jetty.server.handler.AbstractHandler warnings
Merge pull request #471 from mveitas/validation-collections

Add support for performing validation of individual elements of a collection