[maven-release-plugin] prepare for next development iteration
Switch from unreleased JGit 3.4.0 to released JGit 3.3.2

My sincere apologies that I did not detect the "-m7" at the end of the
JGit version number string.  That means we've delivered an unreleased
JGit version to Jenkins users since git-client-plugin 1.9.0.  I don't
think that causes catastrophic harm, since I've seen no JGit related
bug reports since the git client plugin 1.9.0 release.
Update findbugs plugin from 2.5.3 to 2.5.4
Simplify JaCoCo in pom - use defaults

Removes surefire section as part of simplification
Remove guava dependency, provided implicitly by jenkins core dependency

Guava updates can't be managed with "mvn versions:use-latest-releases"
because its version must exactly match the version included in jenkins
core.  Since it must exactly match the version included in Jenkins
core, there is little benefit to declaring the dependency explicitly
in this pom.
Update to latest jacoco release (JDK 8 support update)
Add SmartCredentialsProvider test

An early attempt to more deeply test authentication
and credentials in the plugin.
Add CredentialsProviderImpl test, refactor existing test for some reuse
Add git version parsing test for git 2.0.0 as seen in Debian testing
Test to confirm JENKINS-23424 is a bug in our JGit implementation

JENKINS-23424 reports that a tracked file which is locally modified is
not reset to its original content on the next checkout when using our
JGit implementation.  It is reset to its original content when using
our command line git implementation.
Add test of two arg setAuthor and setCommitter
Update to ssh-credentials 1.7.1
Update to apache httpclient 4.3.4
Update to JGit 3.4.1
Confirm that JGit 3.4.1 [Fixed JENKINS-23424]

Prior to JGit 3.4.1, tracked files which were locally modified were
not reset to their unmodified state by JGit checkout, while the CliGit
arguments used in the same cases would reset the locally modified file
to their unmodified state.
Add test of credentials item clear method
Ignore Netbeans local configuration file
Update severl maven properties so that 'mvn site' succeeds

The parent pom provides outdated versions of the dependency plugin,
the enforcer plugin, the project-info-reports plugin, and the site
plugin.  This overrides those outdated versions with the most current
versions, along with a big comment that will remind us to remove the
override if the parent ever updates to newer versions.
Add functionality for managing refs through the GitClient interface.

It mimics the functionality available for git tags: creation, existence-testing,
deletion, and lookup. It also mimics the behavior: names have spaces replaced
with underscores, creation and update are combined into a single forced
operation, and refs will refer to HEAD.

Unlike tags, refs are bare-boned, and do not include any attached message.
Update findbugs jsr305 dependency to latest (3.0.0)