Add maven prerequisites for dependencies check

Maven plugin version upgrade 1.2 -> 2.1
Add dependencies-check-rules.xml to ignore unreleased versions
Httpcomponents upgrade

4.1.2 -> 4.3.6: tested OK on unit tests and on RundeckMonitor
OWASP A9 fix know vulnérabilies:
CVE-2014-3577: org.apache.http.conn.ssl.AbstractVerifier in Apache
HttpComponents HttpClient before 4.3.5
Deprecation fix apache.httpcomponents

fix deprecation due to apache.httpcomponents upgrade and fixing some
code warnings
Spell correction
Merge pull request #18 from Sylvain-Bugat/pom-update

Http client upgrade to fix CVE-2014-3577