Make Validator interface generic with template
Fix style errors
Merge pull request #203 from takahi-i/genereric-validator

Make Validator interface generic with a template
redpen-189 Migration to Java 8
redpen-189 Migration to Java 8
set jdk to Java 8
redpen-189 Migration to Java 8

"oraclejdk8" is the right one.
 ttp://blog.travis-ci.com/2013-11-18-upcoming-build-environment-updates/
Migrate org.mortbay.jetty.* to org.eclipse.jetty.*.

org.mortbay.jetty* is no longer maintained. It's better to use org.eclipse.jetty*.
Merge pull request #206 from yusuke/jetty-migrate

migrate org.mortbey.jetty.* to org.eclipse.jetty.*
make redpen-server runnable as a standalone war
DocumentValidatorInitializer first looks at ServletContext's attribute and then fallback to context-param.
explicitly specify plugin versions to suppress warning messages upon maven build
Fixes IllegalStateException in the case DocumentValidator gets initialized more than once.
simplified ResourceLoader.

if statements are not necessary.
removed unused field.
private constructor was unused.
Merge pull request #207 from yusuke/web-xml-fallback

make redpen-server runnable as a standalone war
remove redundant string constructions
Merge pull request #209 from recruit-tech/if-not-needed

simplified ResourceLoader.
Merge pull request #210 from recruit-tech/redundunt-string-constructions

remove redundant string constructions
Merge pull request #208 from recruit-tech/pom-warning

suppress build warnings
stop using application attribute
It turns out that use of application attribute was actually unnecessary. It is not type-safe.
stop using Throwable

Catching "Throwable" is generally discouraged. It'll make it difficult to detect the root cause of Errors.
Additionally, applied multi-catch syntax introduced in Java 7.
apply diamond syntax introduced in Java 7