Fixes issue 232

Fixes issue 232 that occurs in at least bash v4.2.25 where "nvm ls" returns "N/A" no matter how many versions of node have been installed.  The fix uses a combination of the find, tr and basename commands instead of basename only.  Tested in bash v3.2.48 and v4.2.25 and zsh v4.3.11.
Fix the 'nvm deactivate' test

`nvm deactivate` does not really remove the nvm command, it just remove
the entries from $PATH and $MANPATH previously adde with `nvm use`.
Fix the setup/teardown urchin test scripts under zsh

The v* glob expansions were failing with an error under zsh, just set
nullglob/NULL_GLOB and make both bash and zsh happier.
Updated fix for issues #232 and #244

Fixes issues #232 and #244 where "nvm ls" returns inconsistent results depending on the number of node versions installed.  This updated fix uses the find and sort commands only.  Tested in bash v3.2.48 and v4.2.25, and zsh v4.3.11.
Merge pull request #229 from em-/testsuite-fixes

Testsuite fixes
Merge pull request #236 from donovanjamesking/master

Fixes issue 232 and "nvm ls" returning "N/A" when it shouldn't