settings: JavaCodeLibrary validation refactored and improved
Added JavaCodeLibrary>>validate which raises JavaCodeLibraryValidationWarnings. Made
JavaCodeBundleEditor to display items with warnings in read.
(grafted from f9d023dc6606374c772cd20eb3cbd85e65181f1f)
<?xml version="1.0" encoding="UTF-8"?>
<classpath>
<classpathentry kind="src" output="bin" path="src"/>
<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
<classpathentry combineaccessrules="false" kind="src" path="/stx.libjava"/>
<classpathentry combineaccessrules="false" kind="src" path="/stx.libjava.libs"/>
<classpathentry combineaccessrules="false" kind="src" path="/stx.libjava.tools"/>
<classpathentry kind="output" path="bin"/>
</classpath>