add source-equivalent function generator
invoke source equivalent generator with debugSource
fix R session crash when returning from top-level debug
initial support for showing file during execution
remove client-side top-level breakpoint injection & stepping
don't re-emit refresh for global environment on stepping
identify and attach special simplifying behavior to source
remove unused debug state; further simplify call stack
initial support for server understanding of function breakpoints
notify server of more breakpoint state changes
correct nested breakpoint state after debugSource
inject breakpoints when debug source is finished
show global environment in picker during debug source
don't auto-advance on client-initiated context depth change
remove all breakpoints more deterministically
don't replay top-level breakpoints when debug source finishes
handle errors occurring during sourcing more gracefully
delay assignment of top-level breakpoints during sourcing
add function attribute identifying error handlers
shift debug frame processing to client