Changed default target definition location from 'src/build' to 'reinforce'
Moved src/* to src/core/*
ExecTarget: start processes in build base directory instead of current working dir
Improved logging in resource collections and JavacTarget
Fix handling of relative paths in single-regular-file resource collections
Added sandbox path and current target tracking in Build
Use build sandbox bath where appropriate
Correctly resolve sandbox path
Added JarTarget
Do not unconditionally load CoreTargetFactory
Fixed build.sh after moving stuff around
More logs in zip and jar targets
Added IvyRetrieveTarget