Added command to get current nvm environment.
Added test for `nvm current`
Universal test of unsetopt command

According to http://stackoverflow.com/a/7522866/189431 it should work in "bash, zsh, ksh and sh (as provided by dash)".
Merge pull request #322 from koenpunt/fix-unsetopt-test

Universal test of unsetopt command. Closes #300
Slurp test unsetopt stderr
Merge pull request #324 from hurrymaplelad/quiet_type

Slurp stderr from  test unsetopt
helper method for testing existence of commands
Merge pull request #326 from koenpunt/has-command-helper

helper method for testing existence of commands
fix copy-packages
fix copy-packages in zsh (without breaking sh and bash)
Merge pull request #327 from stuartf/issue-314

fix copy-packages
merge in changes from creationix/nvm
Merge pull request #328 from naartjie/master

fix copy-packages in zsh (without breaking sh and bash). Closes #223, fixes #299.
Update nvm.sh

small fix fo nvm help info
Update nvm.sh

Fix - this line should be nvm use 0.10 - no 'v', and no incremental version number.
Update README.markdown
Merge branch 'master' into add-current-command
Merge pull request #331 from deiga/patch-1

Update README.markdown
Changed test according to comments
Merge pull request #205 from deiga/add-current-command

Added command to get current nvm environment.