XD-1872 Close Taps pathcache upon ZK disconnect

- In AbstractMessageBusBinderPlugin, close the `taps` PathChildrenCache
upon ZK disconnect. This will avoid existence of multiple `TapsPathChildrenCache`
over period of time (during multiple ZK connect/disconnect)
XD-1831 Mask Database Passwords

* Add module option type `Password`
* In `JdbcConnectionMixin` - Change password property from `String` to type `org.springframework.xd.module.options.types.Password`
* In `DetailedModuleDefinitionResourceAssembler` mask default password module option
* In `JobsController#list()` return PagedResources<JobDefinitionResource> that contain masked passwords in the job definitions
* Create AngularJS directive `xdFormatStream`
* Create unit tests for AngularJS directive `xdFormatStream`
* In `module-create-definition.js` make sure the option type is correctly set
* In `definitions.html` make sure the `xd-format-stream` directive is called
* In `module-create-definition.html` set the form input field to type password, if the module option type is `Password'
* In `module-create-definition.html` set the form input field to be a checkbox, if the module option type is `boolean`
* Add E2E tests `create-new-definition.spec.js`
* In `module-create-definition.html` apply the xd-format-stream directive when outputting the `calculatedDefinition`
* Add `lodash` JS library
* Add Java utility class `org.springframework.xd.dirt.stream.util.StreamUtils`
* Add `StreamUtils#maskPasswordsInStreamDefinition`
* Add unit tests for `StreamUtils#maskPasswordsInStreamDefinition`

Jira: https://jira.spring.io/browse/XD-1831

XD-1831 Code review fixes + polishing

* Admin UI - support Unicode RegEx
* Add XRegExp library (For Unicode support)
* Add support to match both `password` and `passwd` parameters
* Fix `JobsController#list()`
* Fix JavaDoc in `StreamUtilsTests
* Add one more test to `StreamUtilsTests
* Add `toString()` to `org.springframework.xd.module.options.type.Password`
* Add tests for `org.springframework.xd.module.options.type.Password`
* Add more tests to `directives.js`

XD-1831 Fix failing test + rebase with MASTER

XD-1831 Code Review changes - Add JavaDoc

XD-1831 Code Review Changes

XD-1831 Remove `lodash`