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.

bin.includes = META-INF/,\
               xmlunit1.0.jar,\
               tools/,\
               testsupport.jar
jars.compile.order = testsupport.jar
source.testsupport.jar = src/
output.testsupport.jar = bin/