Including build info into application

[local-minimum]

Adding a cli flag:

$ ~/go/bin/rac -version
Version v0.2.0 Commit e39b988 @ 2020-05-25T07:29:30Z

Adding info in the specifications row of the csv headers:

$ head -n 2 out/CCD.csv
CODE,v0.2.0 (e39b988) @ 2020-05-25T07:29:30Z,RAMSES,SPU045-S2:6F,INNOSAT,IS-OSE-ICD-0005:1,Specification,AEZICD002:H
File,ProcessingDate,RamsesTime,...

I tried to directly place the variables in common.Version etc. instead of main.Version but that doesn't seem to work and though a bit ugly perhaps this solution of main transferring its values to common is 🆗 ?

@joakimmoller Is this working on windows?

The if-case in the FullVersion function is mostly there for testing. Building tests with ldflags didn't seem to work and besides this makes tests cases nicer.

Limitation: The version is just the most recent tag on the repository, so if we tag for other reason than making a release it will show that tag instead of the proper version.

Resolves #29

[joakimmoller]

Works fine on windows except for parsing the date.