ivy:report will generate an HTML file that references non-existent ivy-report.css (IVY-826)

Files:
modified: /ant/ivy/core/trunk/src/java/org/apache/ivy/ant/IvyReport.java (try)
modified: /ant/ivy/core/trunk/test/java/org/apache/ivy/ant/IvyReportTest.java (try)
modified: /ant/ivy/core/trunk/CHANGES.txt (try)