Add options to provide default repo/version to eclccserver

To make it easy to submit queries to an eclccserver allow the default repository to be configured. To support this add the following options to eclcc:

--defaultrepo=gch/xxxx
--defaultrepoversion=yyyy
--mainrepo=gch/xxx
--mainrepoversion=yyy

They would be used as follows:

if --main is specified and it does not contain '@', then append mainrepo. If that does not end with a # prefixed version then append mainrepoversion.

So

eclcc --main=demo.main --mainrepo=ghalliday/gch-ecldemo-d --mainrepoversion=version1

would be equivalent to

eclcc --main=demo.main@ghalliday/gch-ecldemo-d#version1

I would also add options mainRepo and mainRepoVersion to eclccserver which would provide default values if not supplied by the query.

Similarly support

eclcc --rootrepo=ghalliday/gch-ecldemo-d --rootrepo=version1

This would add a repository as the default location to find source. It would work with --main, but would also work with a submitted ecl source file.

There would be equivalent ecl options as well.

(Note mainRepo takes precedence over defaultRepo).