Hypelinks between HTML report and landing page dumps

[mauromol]

When using -report -o somepath -rf html -tr --html-path somepath, it would be nice if spid_sp_test created hyperlinks between the index page and the landing page dumps (when clicking on the test number, for instance).

Problem: command line arguments are a bit messy. For this to work all the following conditions must be met:

• reports should be requested (-report)
• the report format must be HTML (-rf html)
• responses should be tested (-tr)
• the report output should be file rather than standard output (-o somepath)
• the landing page dumps should be enabled (--html-path somepath)
• relative links would be preferable, but for security reasons they probably require --html-path argument to be a subfolder of -o argument; in case the latter condition is not met, should absolute file:// links be created? Or should rather hyperlinks not be generated in this case?

[peppelinux]

Many of your claims about the report paramenters have been refactored here, also thanks to your help
https://github.com/italia/spid-sp-test/releases/tag/v0.9.6

I think that hyperlinks from html report to response dumps is a must have.
Before doing that I have to get this done:
#72