DROID should not set query parameters for CGI calls

[jamesaoverton]

At https://github.com/ontodev/droid/blob/master/src/droid/html.clj#L509 we are setting QUERY_STRING for CGI calls, e.g. project-name=ODD&view-path=nanobot.sh/table&branch-name=nanobot. We were using these sometimes for CGI script to include "Back" buttons and stuff. Now they are confusing the new Nanobot code. So I've changed my mind about them. DROID should just use the QUERY_STRING in the request URL, and not change it.

I think that we should set these as environment variables instead: DROID_PROJECT_NAME, DROID_VIEW_PATH, DROID_BRANCH_NAME.