Fix several issues for Linux around casting SDKManager to concrete class:
mostly with reading devices.xml which Unix does not support. Migrated
ISDKManager#getMinimumSupportedSBSv2Version() to API. Can now import and create Symbian projects.
<contexts>
<context id="hoverHelpContext">
<description>Hover Help Guide</description>
<topic href="resources/help context/dl_hover/html/getting_started.html" label="Overview"/>
<topic href="resources/help context/dl_hover/html/setup.html" label="Set Up"/>
<topic href="resources/help context/dl_hover/html/preferences.html" label="Preferences"/>
</context>
</contexts>