Make startup of all elements more useful and consistent

[klausman]

All elements (BS/PS/CS/DS/SIG/dispatcher/SCIONd, possibly more) should log one distinct line on startup, for example:

====================> Starting PathServer ps1-2-3

After this (or on the same line), these things should also be logged:

• Commit ID the binary was built from
• Build date
• Version number, if available
• Build chain version(s) (Compiler versions for gcc and Go)
• Whether the process is dockerized (examine /proc/self/cgroups for that)
• uid/gid the process is running as
• unparsed command line as seen by the process

The clean exit lines should be similarly distinctive (same leader as the start line).

[kormat]

(This is an expansion of the work done in #2014)

[klausman]

This should probably become a library function, at least for Go.

[lukedirtwalker]

Helpful links:
https://socketloop.com/tutorials/golang-add-build-version-and-other-information-in-executables
https://blog.alexellis.io/inject-build-time-vars-golang/

[lukedirtwalker]

We have common startup messages for all go services since #2177. Most services are now go and the rest will be replaced soon, therefore this issue can be closed.