added more docs for the ngx-pcre-stats tool.
docs: minor formatting fixes.
ngx-sample-bt-vfs: removed a legacy comment.
feature: added new tool ngx-sample-bt-off-cpu which can be used to render "off-CPU time flamegraphs".
feature: added new tool ngx-sample-bt-off-cpu which can be used to render "off-CPU time flamegraphs" and analyze the distribution of off-CPU time intervals for any user processes. thanks Brendan Gregg for giving me the inspiration.
ngx-sample-bt-off-cpu: documented the meaning of "1 sample of backtraces".
docs: made it clear that ngx-sample-bt-off-cpu can work on any user processes.
feature: added -u and -k options to ngx-sample-bt-off-cpu for sampling either the userland or kernel space backtraces or even both.
feature: added new tool ngx-recv-queue for analyzing TCP receive queueing latencies.
docs: minor wording fixes for ngx-recv-queue.
ngx-recv-queue: attempted to support older kernels (as old as 2.6.37); also added source port to the keys for the associative array recording the queueing latency.
added docs for ngx-accept-queue and ngx-recv-queue regarding the requirement of compiling the linux kernel with gcc 4.5+ and DWARF 3+.
added copyright notices to all the tools' source.
typo fixes in the usage text for ngx-sample-bt-vfs and ngx-sample-bt-off-cpu.
feature: added new tool ngx-accessed-files for finding file names that are being read or written.
feature: ngx-accessed-files: documented the -l option and also tweaked the wording in docs a bit.
docs: fixed the path to nginx in samples.