Fixed a bug where --silent mode was failing for nvm use I ran a test
that just ran ```nvm use node --silent``` that I wrote by myself.
Unfortunately I noticed a bug where it still prints out some messages in
different cases. This pull request is to fix that bug. * Added in an argument
called ***quiet*** to the nvm_rc_version() function at *line 339* * Printed
anything inside the nvm_rc_version() only in the scenario where quiet mode is
off * Ran the nvm_rc_version() function in quiet mode only if silent mode is
on in the "use" command of nvm at *line 2990* * Ran *nvm_echo* and *nvm_err*
inside the "use" command of nvm only in the scenario where silent mode is off
(There were 4 scenarios where this was forgotten) * Edited the ```nvm
deactivate``` command to include a silent mode * Changed the help page to
include the --silent option for ```nvm deactivate``` * Added in aliases for
the --silent flag in ```nvm deactivate``` and ```nvm use``` * Used silent
mode inside the ```nvm use``` when running ```nvm deactivate``` inside it and
silent mode is on A test was attached in the 'test/slow/nvm use' directory.
It is named *Running "nvm use node --silent" doesn't print anything*. It runs
```nvm use node --silent and checks``` and succeeds if the OUTPUT matches the
EXPECTED_OUTPUT which is *null* or *''*. When the test was run locally, it
still ouputed results if someone deleted some contents of the *.nvm/* folder.
This output was given from the ```nvm deactivate command```. This was the
reason that the ```nvm deactivate``` was edited to include silent mode.
nmarghetti