Refactor getBuiltInMacros() to be SBSv1 specific. This are the hard-coded macros misc macros we are adding for SBSv1.
For SBSv2, they are retrieved from the sbs config query. Also, clean up some API and comments on public APIS
<?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>