Adding a user agent configuration field to HttpClientConfiguration, and a default user agent to HttpClients, consisting of "{serviceName} ({clientName})"
Adding a test for setting the http client user agent
Allow configuration of stackTracePattern via SyslogAppenderFactory
Renamed stackTracePattern to stackTracePrefix
Updated docs to explain the syslog appender exception to the standard prefix rule
Add `--catalog` and `--schema` to AbstractLiquibaseCommand, fixes #584
Merge pull request #590 from joschi/584-db-dump-schema

Add `--catalog` and `--schema` to AbstractLiquibaseCommand
Merge pull request #586 from stuartgunter/syslog

Allow configuration of stackTracePattern via SyslogAppenderFactory
update migration docs, added details about `--schema` and `--catalog`

As the migrations are update by yoschi (fix #590) a little time ago, I am updating the docs related to it.
Merge pull request #591 from DheerendraRathor/patch-1

update migration docs, added details about `--schema` and `--catalog`
Fix typo in dropwizard-migrations docs
Enable validation of Optional values

To validate values contained in an `Optional` type, we need to use a new
feature in Hibernate Validator 5.1, so this introduces a dependency
version bump to 5.1.1.

This makes use of an *experimental* feature in Hibernate Validator, so
I'm not 100% sure we'll want to make use of it yet.

To validate the contents of an `Optional`, you need to include an
`@UnwrapValidatedValue` annotation on the property being validated:

```java
@Length(min = 32, max = 32)
@UnwrapValidatedValue
private Optional<String> md5 = Optional.absent();
```

Absent values are considered `null` when validated, so their behaviour
depends on your chosen constraints' handling of `null` values.

We have to register this inside `Bootstrap`, and I noticed that we don't
(currently) expose a way for users to register more validation behaviour
through `Bootstrap`, so we should probably look in to that.
Merge pull request #594 from dropwizard/feature/validate-optional-values

Enable validation of (Guava) Optional<T> values
Changing HttpClientConfiguration.setUserAgent and HttpClientConfiguration.getUserAgent to match types
Merge pull request #582 from reines/default_user_agent

Make User-Agent for HttpClient configurable