reflow some comments
support msvc /RTC option and make run_regression_tests support passing on arbitrary boost-build options (to allow different testers enable rtc and sanitizers)
fix sanitize=rtc option in Jamfile
make all unit tests pass msvc's /RTCc instrumentation (no implicit integer truncation in casts)
merged storage allocation mode fix from RC_0_16
merge invalid assert fix from RC_0_16
include reason in peer_blocked_alert
fix export of upnp error category function
merged SetFileValidData fix from RC_0_16
update Changelog
fix millisecond <-> microsecond mixup in disk stats for cumulative time counters
failed to count iops for read operations in some cases
active_loaded_limit=0 means unlimited
default loaded limit is 100
fix typo
merged mingw fix from RC_0_16
merged changes from trunk
improve error messages when the user-load function fails to load a torrent
check torrents in order of their sequence number, instead of random
network threads still appear to have race conditions. set default back to 0