Less errors in equoIde

[blacelle]

This follows #1523

• I cleaned some resources files named XXX.java, leading to warnings in EquoIde.
• In macOs, equoIde icon (on Cmd+Tab) is a folder which is slightly confusing
• Tried starting CleanthatJavaRefactorerTest.testEna4bleDraft() as a JUnit Test:
  
  We used to have similar issues from IntelliJ.

org.opentest4j.AssertionFailedError: System property 'spotlessMavenPluginVersion' is not defined
	at org.junit.jupiter.api.AssertionUtils.fail(AssertionUtils.java:38)
	at org.junit.jupiter.api.Assertions.fail(Assertions.java:135)
	at com.diffplug.spotless.maven.MavenIntegrationHarness.getSystemProperty(MavenIntegrationHarness.java:283)
	at com.diffplug.spotless.maven.MavenIntegrationHarness.buildPomXmlParams(MavenIntegrationHarness.java:243)
	at com.diffplug.spotless.maven.MavenIntegrationHarness.createPomXmlContent(MavenIntegrationHarness.java:218)
	at com.diffplug.spotless.maven.MavenIntegrationHarness.createPomXmlContent(MavenIntegrationHarness.java:214)
	at com.diffplug.spotless.maven.MavenIntegrationHarness.writePom(MavenIntegrationHarness.java:182)
	at com.diffplug.spotless.maven.MavenIntegrationHarness.writePom(MavenIntegrationHarness.java:178)
	at com.diffplug.spotless.maven.MavenIntegrationHarness.writePomWithJavaSteps(MavenIntegrationHarness.java:126)
	at com.diffplug.spotless.maven.java.CleanthatJavaRefactorerTest.testEnableDraft(CleanthatJavaRefactorerTest.java:30)

• In Eclipse, I'm used to m2e-core. Gradle support in Eclipse is (in my experience) quite poor.
• This enables a very quick IDE, without having to install Eclipse manually. That's great for new-comers or restricted environnement (e.g. while working in a customer environment with restrictive security constrains).

[nedtwigg]

Thanks very much for the feedback! I think that Equo will be able to improve the Gradle experience in the medium term, but we'll see. Regarding m2e, Equo will be adding that in the coming weeks.

• Use m2e to import "this" project equodev/equo-ide#18

[nedtwigg]

Also, the tests were all failing in your earlier commit because the formatters don't change class LiteralsFirstInComparisons_dirty to class LiteralsFirstInComparisons_clean. I added a commit that renames the .java to .test which is the workaround we've been using for other java formatters. Is that okay with you?

[blacelle]

Is that okay with you?

Fine, thanks. More comfortable for me to name such test files with the proper file extension, but it is a very low deal.