Switch to C++11

[Flowdalic]

This PR is, for now, primary to check if travis would fail with C++11 and as basis for discussion. Related to #4126 (comment).

[AenBleidd]

Travis CI will not fail, but AppVeyor will

[AenBleidd]

And I'm afraid, you'll have to wait ~2 hours because currently Travis CI is not usable because of their new policies

[Flowdalic]

Travis CI will not fail, but AppVeyor will

FYI AppVeyor did not fail. Not sure what to make of it, hoping that it could mean that BOINC could easily switch to C++11, but I somehow expect that you will teach me better. :)

[AenBleidd]

FYI AppVeyor did not fail

Because you changed only build instructions for linux. But if you include any C++11 instruction - AppVeyor will fail because Visual Studio 2010 has not C++11 support

[talregev]

Why we still support vs2010?

[AenBleidd]

@talregev because this will not be true soon 😜

[talregev]

@AenBleidd That is great news! :)

[AenBleidd]

This is not needed anymore

[Flowdalic]

Great. \o/

With which commit did the upgrade to a new C++ standard version happen?

[AenBleidd]

This decision was made offline and no commit was required. But if you need some as a start point, then it could be this one: 180ea88