Update boost and python-cmake

[o01eg]

Extracted from #48.

Updates boost to 1.69, next version update is in #50.

Should be usable even with python2 only support.

[o01eg]

@adrianbroher I've updated boost to 1.68 and changed some gil patches, could you review it?

[o01eg]

It looks like boost >= 1.67 requires to add bcrypt.lib on windows boostorg/uuid#68

[o01eg]

Next thing I catch is boostorg/python#212

[o01eg]

There is a bug in python's pyerror.h redefines snprinf after upgrading boost to 1.69

https://bugs.python.org/issue36020
nlohmann/json#1408

[o01eg]

I've fixed pyerror.h in generated SDK and freeorion builds and runs, but I suppose patches to python should be applied with python-cmake.

[o01eg]

I've prepared patch for python-cmake but it failed for apply on python with windows EOL. If I converts it to unix EOL it failed to apply on python-cmake.

[o01eg]

I've updated boost to 1.70 but found errors about missing gil files boost/gil/gil_config.hpp and boost/gil/extension/io/io_error.hpp. Could someone help with it?

[o01eg]

I've split out boost 1.69 to 1.70 so it possible to merge this PR now.

[geoffthemedio]

I've split out boost 1.69 to 1.70 so it possible to merge this PR now.

But pull request 50 is listed as superseding this. Which should be merged?

[o01eg]

But pull request 50 is listed as superseding this. Which should be merged?

#50 still has unsolved issues so only this PR could be merged.