swc-installation-test-2.py: Comment out 'mercurial' dependency
swc-installation-test-2.py: Comment out 'mercurial' dependency

There can be trouble detecting the Python package, especially on MS
Windows where the installed version of Python used to run the script
may not know about installed version of Mercurial.  Because nobody is
likely to use Mercurial's Python interface in a SWC class (they'll
probably stick to the command line interface), comment out this
dependency.

selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest