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().
bin.includes = plugin.xml,\
META-INF/,\
html/,\
index/,\
uiqTOC.xml,\
tocConcepts.xml,\
tocReference.xml,\
tocRelease.xml,\
tocStart.xml,\
tocTasks.xml,\
reference/,\
book.css