Add missing EXPORT_C in cpp files, and reinstate the DEF file additions, to fix Bug 2473
Mystery solved - RVCT 2.2 only exports functions on the basis of EXPORT_C, but RVCT 4.0 is triggered by the IMPORT_C as well
<?xml version="1.0"?>
<!DOCTYPE SystemDefinition SYSTEM "sysdef_1_4_0.dtd"[
<!ENTITY layer_real_source_path "sf/app/photos" >
]>
<SystemDefinition name="photos" schema="1.4.0">
<systemModel>
<layer name="app_layer">
<module name="photos">
<unit unitID="uxdo.photos" mrp="" bldFile="&layer_real_source_path;/group" name="photos" />
</module>
</layer>
</systemModel>
</SystemDefinition>