Stackcollapse perf streaming

[randomstuff]

This may be used to sample from a larger set of data:

perf script |
./stackcollapse-perf.pl --stream |
shuf -n 50000 |                              # Take 50000 random lines/samples
./stackcollapse-sum.pl |
./flamegraph.pl

[mamonney]

Suggested change

	--event-filter=EVENT # event name filter\n
	--streaming # stream the stacks without summing them\n
	--event-filter=EVENT # event name filter
	--streaming # stream the stacks without summing them\n

[randomstuff]

Fixed, thanks.

[brendangregg]

Ok, but can you please add docs to README.md under the Options section to include that one-liner? People won't know how to use this option without those docs.

[randomstuff]

I've added some documentation in the README.

[randomstuff]

Fixed conflicts with #289. Taking random samples with shuf does not make as much sense when the samples do not have the same weight.