Start work to move to running under Jenkins; use .dcfg files by calling GetEnvironment rather than ⎕json

[dyaandys]

So far we've used ⎕json to parse the .dcfg files - but we need to be able to pick up $WORKSPACE (aka [WORKSPACE]) so get the contents by using GetEnvironment. That means that INTERVAL needs to be converted into a number.

Add logging information for when there are no new/changed issues - then we know that something has happened.

There will be more scripts etc created for SSGMon to run under Jenkins ..