When scanning system drives for installed SDKs, default SDK version to 5.0 when no SDK version info is available; also updated SDK properties dialog to correctly display SDK version string.
<?xml version="1.0" encoding="UTF-8"?>
<classpath>
<classpathentry kind="src" path="src"/>
<classpathentry sourcepath="JRE_SRC" kind="var" rootpath="JRE_SRCROOT" path="JRE_LIB"/>
<classpathentry kind="con" path="org.eclipse.pde.core.requiredPlugins"/>
<classpathentry kind="output" path="runtime"/>
</classpath>