[NEXUS-5822] replace the call to ConcurrentHashMap.containsKey with the content of that method in Java 8 b102 with get prefixed by super. thereby preventing the recursion

Ported changes from
https://github.com/sonatype/nexus-oss/pull/89
Add an UniformInterfaceException hamcrest Matcher

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Add a base interface for clients accessing a siesta endpoint

This will trigger known error/validation error filters

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Since JS/resources mentioned here are in JAR, this is unusable
[NXCM-5498] Html encode of displayed error message

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge remote-tracking branch 'origin/master' into NEXUS-5490-remote-user