Modify for Ubuntu 14.04 version

[llFreetimell]

In Ubuntu 14.04 version, there are problems as below.

1. There is no clang-format package.

   seok@ubuntu:~/mengde$ ./ci/install_deps_ubuntu.sh 
   Reading package lists... Done
   Building dependency tree       
   Reading state information... Done
   E: Unable to locate package clang-format

2. Requested version of boost is 1.55, not 1.52. And also libboost-all-dev package in Ubuntu 14.04 is 1.54 version.

   ...
   CMake Error at /usr/share/cmake-2.8/Modules/FindBoost.cmake:1131 (message):
   Unable to find the requested Boost libraries.
   
   Boost version: 1.54.0
   
   Boost include path: /usr/include
   
   Detected version of Boost is too old.  Requested version was 1.55 (or newer).
   Call Stack (most recent call first):
   CMakeLists.txt:37 (find_package)
   ...

Therefore, I modified to use clang-format-3.4 and boost1.55 in Ubuntu 14.04 environment. After modifying, I did build test and confirmed the result program runs well.

[llFreetimell]

After I finished build in Ubuntu 14.04, I failed to play game, specifically when I click the 'example' button. And then I updated to Ubuntu 16.04, I succeeded. I don't know it is problem of Ubuntu version or my mistake.

[wateret]

@llFreetimell Have you tried changing the version of boost? Or could you try with 1.52 by changing this line? https://github.com/wateret/mengde/blob/master/CMakeLists.txt#L37

Maybe 1.52 could be just enough :)

[llFreetimell]

I was supposed to try by changing that line, but dependencies of boost are twisted. I will try it ASAP.

[llFreetimell]

Do you still have willing to support Ubuntu 14.04? After some changes applied, specific minimum versions of cmake and clang-format is required. If you want to do so, modifications of build document and other codes are needed I think.

[wateret]

@llFreetimell Actually at first I thought it would be nice to support 14.04. However now the situation has changed, so probably supporting it is not worth it. Here are the reasons why.

• Some system packages will require higher version from default version from apt.
  • CMake 3.1+ (Ubuntu 14.04 apt has 2.8)
  • G++ 5+ (Ubuntu 14.04 apt has 4.x)
  • boost 1.52+ (Ubuntu 14.04 apt has ???)

Of course one can install recent versions for those packages with other ways, then it will work. However I think it is not worth consistently maintaining that in our repo :)

[wateret]

@llFreetimell BTW, changing required boost version is still acceptable. With either way:

• Change the version of required boost to 1.55 from the document file
• If you can check if 1.52 version of boost works, you can update required boost to 1.52 from CMake file. https://github.com/wateret/mengde/blob/master/CMakeLists.txt#L43

[llFreetimell]

I close this PR since we talked in offline.