[FIXED JENKINS-21254] Ensuring that all <link>s offered on the /login page can be read even by anonymous users without Jenkins.READ.

Various translation fixes

Added some french translations

Added some french translations

https://trello.com/c/MhG9Ksqa/12-windows-service-slave-launcher

First tried using excludedGroups and trying to work around SUREFIRE-984.
Made some progress, but not ideal since marked tests are omitted from output, rather than being listed as ignored.
Throwing AssumptionViolatedException from JenkinsRule is much simpler and seems to work better.
https://github.com/junit-team/junit/issues/116 notes its limitations.

The jenkins_main_trunk job has been retired, so for now just skip these tests when running on any Jenkins server.

[JENKINS-18410] NPE from previous fix (fcdf7499) under some conditions, which the test case was not exercising.
java.lang.NullPointerException
	at hudson.tasks.test.AggregatedTestResultPublisher$TestResultAction.getProject(AggregatedTestResultPublisher.java:173)
	at hudson.tasks.test.AggregatedTestResultPublisher$TestResultAction.<init>(AggregatedTestResultPublisher.java:146)
	at hudson.tasks.test.AggregatedTestResultPublisher$TestResultAction.<init>(AggregatedTestResultPublisher.java:135)
	at hudson.tasks.test.AggregatedTestResultPublisher.perform(AggregatedTestResultPublisher.java:90)

Fingerprinter calls rebuildDependencyGraphAsync, so since this is now delayed by 500msec, tests incorrect as of 1.522 will now fail pretty reliably unless made to forcibly rebuild the graph.

[JENKINS-20772] Fix scrolling

Noting yet another weird problem with BuildTrigger’s reliance on DependencyGraph for its own execution.
Since this is now (1.522) updated asynchronously, the value may not actually be correct, potentially causing erratic behavior especially in tests.

[JENKINS-20772] Only show error message in dialog

This change removes the superfluous UI elements around the error
message if possible. Otherwise, fall back to existing behavior
of adding entire page to iframe.