Add provider attribute into gerrit events
Add trigger parameters using provider attribute in extended event

The below are added to triggered build.

GERRIT_NAME
GERRIT_HOST
GERRIT_PORT
GERRIT_PROTO
GERRIT_VERSION
Add 'url' key in provider attribute

Gerrit FrontEnd URL should be have by each gerrit hosts.
So add it to provider attribute.
In addition, improve class which treats the frontend URL.
Fix checkstyle issue and test code.
Fix null pointer access

Provider attribute as user defined has possibility not to exist.
So you need to check pointer before calling methods.
Add getGerritFrontEndUrlFor(event) then refactor related codes.
Add interface then implement to create map object
[maven-release-plugin] prepare release gerrit-trigger-2.10.0
[maven-release-plugin] prepare for next development iteration
Merge pull request #52 from rinrinne/provider-attribute

Add trigger parameters using provider attribute
Update build-config dependency versions
Small Provider refactor while fixing test regressions

SpecGerritTriggerHudsonTest.testDoubleTriggeredBuildOfDifferentType
is still failing.
Remove unused import
Add help for provider parameters
small change
One more checkstyle fix
Merge pull request #56 from rinrinne/fixstyle

Remove unused import
Merge pull request #57 from rinrinne/parameter-provider

Add help for provider parameters
Delay connection until Jenkins completes to load all items.

Configured gerrit triggered job cannot take any gerrit events until
it is loaded to Jenkins. So stream-events connection should be delayed
until Jenkins completes to load all items.
Nullpointer when project cant be resloved

When getting Gerrit parameters the project is needed to sort
out if Name/Email should be fetched or if escapeQoutas is needed.

But if the project doesn't exist when triggered manually a
nullpointer is thrown.

Added nullpointer check and default values if project is missing.
Added method setOrCreateParametes without parameter project

Change-Id: I72fc2812073772024d837d392b09e34bf041aac9