remove eof whitespace lines

Summary:
Remove lint errors from folly: trailing newlines

find folly | xargs arc lint | grep -B3 EOF | grep ">>>" | egrep -o "folly[^:]*" | xargs -n1 sed -i '$d'

folly/experimental/io/test/AsyncIOTest.cpp had two trailing newlines,
the second was removed by hand

@override-unit-failures

Test Plan:
fbconfig -r folly && fbmake runtests

Pretty overkill for a whitespace diff, but why not.

Reviewed By: robbert@fb.com

Subscribers: sdwilsh, fugalh, njormrod

FB internal diff: D1561213
fix race in Future::waitWithSemaphore

Summary:
There's a race condition in waitWithSemaphore, specifically because we're
returning a new future that's completed by the input future. As a result,
that future may not be completed by the time waitWithSemaphore returns,
although completion should be imminent.

Test Plan:
`var=0; while true ; do echo $((var++)); _bin/folly/wangle/wangle-test --gtest_filter='Future*' || break ; done`

Before change two runs yielded 303 and 371.

After change I killed the test at 11000.

Reviewed By: njormrod@fb.com

Subscribers: fugalh, njormrod

FB internal diff: D1561281

Tasks: 5180879
Remove dependency on std::to_string

Summary:
Mobile platform clang doesn't currently support std::to_string
so remove folly's dependency on it.

Test Plan: existing tests

Reviewed By: mpawlowski@fb.com

Subscribers: kmdent, fma, benyluo, shikong, ranjeeth, subodh, pgriess, njormrod

FB internal diff: D1562179

Tasks: 5183325
merge https://github.com/facebook/folly/pull/88

Summary:
merge https://github.com/facebook/folly/pull/88, missing install header

Looks like fbthrift build needs this

Test Plan: watch jenkins build still works

Reviewed By: ckwalsh@fb.com

Subscribers: doug, njormrod

FB internal diff: D1563651
Bump version to 8:0