major refactor to wrap retieval of macros all around ISymbianBuildContext, to avoid need to access internal apis. Added getTargetTypeMacro(String targettype),
List<IDefine> getMetadataMacros(), List<IDefine> getBuildMacros().
<contexts>
<context id="viewer" title="Sample View">
<description>This is the context help for the sample view with a table viewer. It was generated by a PDE template.</description>
<topic href="/PLUGINS_ROOT/org.eclipse.platform.doc.isv/guide/ua_help_context.htm" label="Context-sensitive help">
<enablement>
<with variable="platform">
<test property="org.eclipse.core.runtime.isBundleInstalled" args="org.eclipse.platform.doc.isv"/>
</with>
</enablement>
</topic>
</context>
</contexts>