[~] fix plugin pj

https://github.com/robbyrussell/oh-my-zsh/commit/bce74975d055529cbd186782e2fd99e6da840460
Switch back to oh-my-zsh.hide-dirty setting again

Commit 81004dfaba509ff62a13ba303ab941938d619326 reverted the change
in 9b811fb625c03c30a766191cdf65a1c7c1fd96b2 when editing the merge
conflict from #2928.

This commit fixes that so that we don't make the same mistake again.

First seen in http://git.io/Cdaj5Q
Merge pull request #3323 from alfss/fix-pj

[~] fix plugin pj
Merge pull request #3333 from mcornella/fix-git-hide-dirty

Switch back to oh-my-zsh.hide-dirty setting again
Force ssh-agent output to use bourne-style syntax

On systems where the shell cannot be changed because of a strict
security policy, ssh-agent will use the syntax of whatever the
default $SHELL is.
For instance, if the default shell is tcsh, ssh-agent will use the
c-shell style (setenv).

This change forces ssh-agent to use bourne-style syntax since that
has to be later interpreted by zsh. Consequently, the environment
file will contain `export' statements from now on (instead of
`setenv').