add jaeger support, link hot container & req span (#840)

* add jaeger support, link hot container & req span

* adds jaeger support now with FN_JAEGER_URL, there's a simple tutorial in the
operating/metrics.md file now and it's pretty easy to get up and running.
* links a hot request span to a hot container span. when we change this to
sample at a lower ratio we'll need to finagle the hot container span to always
sample or something, otherwise we'll hide that info. at least, since we're
sampling at 100% for now if this is flipped on, can see freeze/unfreeze etc.
if they hit. this is useful for debugging. note that zipkin's exporter does
not follow the link at all, hence jaeger... and they're backed by the Cloud
Empire now (CNCF) so we'll probably use it anyway.

* vendor: add thrift for jaeger

vendor/git.apache.org/thrift.git/build/travis/installCXXDependencies.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+
+# Mainly aiming Travis CI's Ubuntu machines for now
+# see what we need: http://thrift.apache.org/docs/install/ubuntu
+
+# General dependencies
+sudo apt-add-repository "deb http://archive.ubuntu.com/ubuntu/ trusty main restricted" -y
+sudo apt-get update -qq
+
+sudo apt-get install -qq libpango-1.0-0 libqt4-dev qtbase5-dev qtbase5-dev-tools qt5-default libboost-dev libboost-test-dev libboost-program-options-dev libboost-system-dev libboost-filesystem-dev libboost-thread-dev libevent-dev automake libtool flex bison pkg-config g++ libssl-dev make cmake git debhelper bc nsis ninja-build
+dpkg -S /usr/include/boost/version.hpp

vendor/git.apache.org/thrift.git/build/travis/installDependencies.sh

@@ -0,0 +1,66 @@
+#!/bin/sh
+
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+SCRIPTPATH=$( cd $(dirname $0) ; pwd -P )
+
+# Mainly aiming Travis CI's Ubuntu machines for now
+# see what we need: http://thrift.apache.org/docs/install/ubuntu
+
+# Java dependencies
+sudo apt-get install -qq ant openjdk-7-jdk
+sudo update-java-alternatives -s java-1.7.0-openjdk-amd64
+
+# Python dependencies
+sudo apt-get install -qq python-all python-all-dev python-all-dbg python-setuptools python-support python-twisted python-six python3-six
+
+# Ruby dependencies
+sudo apt-get install -qq ruby ruby-dev
+sudo gem install bundler rake
+
+# Perl dependencies
+sudo apt-get install -qq libbit-vector-perl libclass-accessor-class-perl libio-socket-ssl-perl libnet-ssleay-perl libcrypt-ssleay-perl
+
+# Php dependencies
+sudo apt-get install -qq php5 php5-dev php5-cli php-pear re2c
+
+# GlibC dependencies
+sudo apt-get install -qq libglib2.0-dev
+
+# Erlang dependencies
+sudo apt-get install -qq erlang-base erlang-eunit erlang-dev erlang-tools rebar
+
+# GO dependencies
+echo "golang-go golang-go/dashboard boolean false" | debconf-set-selections
+sudo apt-get -y install -qq golang golang-go
+
+# Haskell dependencies
+sudo add-apt-repository -y ppa:hvr/ghc
+sudo apt-get update
+sudo apt-get install cabal-install-1.20 ghc-$GHCVER
+
+# Lua dependencies
+sudo apt-get install -qq lua5.2 lua5.2-dev
+
+# Node.js dependencies
+sudo apt-get install -qq nodejs nodejs-dev npm
+sudo update-alternatives --install /usr/bin/node node /usr/bin/nodejs 10
+
+# CSharp
+sudo apt-get install -qq mono-gmcs mono-devel libmono-system-web2.0-cil
+sudo apt-get install -qq mingw32 mingw32-binutils mingw32-runtime nsis