Assets controller fixes

* Replace usages of Play.current with Play.maybeApplication. This
  ensures that at very least templates using assets reverse routes can
  be rendered without a running application.
* Used Option instead of exceptions to handle NotFound
* Fixed resource leak in digest cache
* Use Global bad request handling
* Let Play handle errors
[DOC] Fix jpa config example
Merge pull request #3125 from cedricziel/jpaDocFix

[DOC] Fix jpa config example
Document form mappings for other date types
Merge pull request #3126 from richdougherty/date-docs

Document form mappings for other date types
modify version number

0.1.3 --> 0.1.4
Merge pull request #3128 from diceit/ide-ensime-014

modify version number for ensime in doc
Merge pull request #3122 from jroper/assets-no-play-current

Don't use Play.current anywhere in Assets
Test for HTTP calls