"lexicographic" parameter sometimes ignored in ImportsChecker

[nrinaudo]

Steps to reproduce

Have a file containing the following import statement:

import java.time.{ZoneOffset, ZonedDateTime}

And run scalastyle with the following configuration:

  <check class="org.scalastyle.scalariform.ImportOrderChecker"               level="error"   enabled="true">
    <parameters>
      <parameter name="groups">all</parameter>
      <parameter name="group.all">.+</parameter>
      <parameter name="lexicographic">true</parameter>
    </parameters>
  </check>

Expected behaviour

Scalastyle should not find an issue

Observed behaviour

Scalastyle complains:

ZonedDateTime should come before ZoneOffset.

Notes

I believe this is a bug because it seems to contradict the lexicographic parameter's documentation:

 *  - lexicographic: if true, imports are ordered lexicographically (classes, wildcards, then
 *                   packages; case-sensitive ordering within); 

It also disagrees with tools such as scalafmt - and having scalafmt and scalastyle disagreeing on how things should be ordered is not fun.

I'm happy to submit a PR for this issue - it looks like a simple omission in compareNames in the case isImport=false, which ignores the value of lexicographic and will always compareIgnoreCase.