Update/review/create dev and test docs

[danshearer]

The documents development.md and to a lesser extent INSTALL.md contain instructions that are either too much, too little or lack context. They are also effective, if you pick through the right bits.

This issue is to go through every single step to make sure it is exactly correct, and that it is consistent with the context and limitations listed over in system-modeller-deployment's INSTALL.md, which is much more up-to-date than the one here in system-modeller.

This is also related to the release process (which is only partly documented atm, see #185 ) because if we aren't testing a particular deployment scenario when making a release, then that scenario is not supported. This may mean that we drop support for a platform, or, we need to ask for more resources to do the testing, or, we improve our automated test deployment scripts. In any case, this needs to be gone through line-by-line.

[danshearer]

Something we don't cover anywhere is how to switch between release versions. Given Spyderisk is early stage software this is important so users can relatively easily do their own triage such as "this works in vesion X but not version Y". Equally important is how to run multiple different versions concurrently, for the same reasons. Showing users how to do this gives us better quality bug reports. Particularly if a particular system model works differently between versions in a way we did not expect.