Option '--templates' for the 'update' command.
Changed names for project dir variables/arguments.

Since 'sourceDir' and 'destDir' already default to 'website/input'
and 'website/output' respectively and the README uses the
the term 'output' anyway 'sourceDir' has been renamed
'inputDir' and 'destDir' has been renamed 'outputDir'.
Tests for Tclssg project init and build.