Make deprecations and feature flag more explicit in compile output

[fmasion]

When compiling there's a lot of deprecation and feature warnings suggesting to re-run with -feature and -deprecation

There's event more in test cases but tests are very verbose so it's not easy to clearly see them

running sbt commands

• clean
• test:compile will show 179 WARNINGS without any detail about which file/line are concerned

Moreover there are many more compiler flag's that could help be aligned with the high quality requirements of this project. These flags however could be activated later on

I suggest to create a compileOptions.sbt (see gist) file with all these flags and activate them on your choice progressively.