add libboost back to build system

.travis.yml

@@ -8,7 +8,7 @@ before_install:
 - sudo add-apt-repository --yes ppa:ubuntu-toolchain-r/test
 - sudo apt-get update -qq
 - sudo apt-get -y install gcc-4.8 g++-4.8
-- sudo apt-get -y install git cmake make pkg-config libpng-dev
+- sudo apt-get -y install git cmake make pkg-config libboost-dev libpng-dev
 - sudo apt-get -y install libxi-dev libglu1-mesa-dev x11proto-randr-dev x11proto-xext-dev libxrandr-dev x11proto-xf86vidmode-dev libxxf86vm-dev
 
 install:

src/text/placement.cpp

@@ -6,6 +6,8 @@
 #include <llmr/util/math.hpp>
 #include <llmr/util/constants.hpp>
 
+#include <algorithm>
+
 using namespace llmr;
 
 const int Placement::tileExtent = 4096;

src/text/rotation_range.cpp

@@ -1,6 +1,7 @@
 #include <llmr/text/rotation_range.hpp>
 
 #include <cassert>
+#include <algorithm>
 
 namespace llmr {