drop experimental key
'preload build process' optimization, initial (off in registry by default).
once preloaded process has been started, it should be used by the next compile session (incomplete)
ensure right launching sequence for preloaded build processes
refreshing generated roots in one refresh session to avoid multiple 'roots changed' events (IDEA-131634)
hanging pre-loaded processes problem: additional logging
waiting for process handler in loop, until the process really exits
do not start excessive number of pre-loaded processes
wait for cancelled process termination on processHandler instead of Future object;
correctly unregister Future object for cancelled preloaded process;
better launching errors diagnostic for preloaded processes
enabling process pre-load optimization by default
do not refresh output roots after up-to-date or cancelled build session
logging pre-load process timings
preloading builders and target states
ensure exiting of waiting preloaded processes on cancel
reliably call exit()
preventing NPE
ensure model is loaded if FS rescan is forced
enable 'exit-if-no-events' startup optimization for preloaded process
force netty to use Log4J logger implementation
recompile classes with potentially ambiguous method calls when vararg method is added