Enforce dependencies versions

[decebals]

This PR check the dependency version declared in plugin metadata (see PluginDescriptor.getDependencies() -> PluginDependency.getPluginVersionSupport()).
The important method is DependencyResolver.checkDependencyVersion().
The actual implementation is:

/**
 * Check if an existing version of dependency is compatible with the required version (from plugin descriptor).
 *
 * @param requiredVersion
 * @param existingVersion
 * @return
 */
protected boolean checkDependencyVersion(String requiredVersion, Version existingVersion) {
    return existingVersion.satisfies(requiredVersion);
}

DependencyResolver class is capable now to offer additional information via DependencyResolver.Result object returned by public Result resolve(List<PluginDescriptor> plugins) method:

public static class Result {

    private boolean cyclicDependency;
    private List<String> notFoundDependencies; // value is "pluginId"
    private List<String> sortedPlugins; // value is "pluginId"
    private List<WrongDependencyVersion> wrongVersionDependencies;

    // getters

}

public static class WrongDependencyVersion {

    private String dependencyId; // value is "pluginId"
    private String dependentId; // value is "pluginId"
    private Version existingVersion;
    private String requiredVersion;

    // getters

}

The actual implementation allows you to stop the application if something is wrong with the dependencies (the default behavior) via:

• DependencyResolver.CyclicDependencyException
• DependencyResolver.DependenciesNotFoundException
• DependencyResolver.DependenciesWrongVersionException

or to try to eliminate the plugins with problems and start the application only with the plugins that are OK.

[coveralls]

Coverage decreased (-0.6%) to 52.133% when pulling 7814de4 on dependencies into a9c70ff on master.

[coveralls]

Coverage increased (+1.9%) to 54.614% when pulling 3261133 on dependencies into a9c70ff on master.

[coveralls]

Coverage increased (+1.9%) to 54.614% when pulling 1661d30 on dependencies into a9c70ff on master.

[coveralls]

Coverage increased (+2.0%) to 54.694% when pulling d77cfad on dependencies into a9c70ff on master.