Escape SSH commands correctly

[prudloff-insite]

Overview

This pull request:

• Fixes a bug
• Adds a feature
• Breaks backwards compatibility
• Has tests that cover changes
• Adds or fixes documentation

Summary

This changes the way SSH commands are escaped in order to work with commands containing '.

Description

Consider the following code:

    $gitTask = $this->taskGitStack()
      ->commit('foo bar');

    $this->taskSshExec()
      ->exec($gitTask)
      ->run();

Without this patch, it will produce (which will fail):

ssh server 'cd "/path/" && git commit -m 'foo bar''

And with the patch:

ssh server 'cd "/path/" && git commit -m '\''foo bar'\'''

(Now the Git message is escaped correctly.)

Sorry, we are still stuck on Robo 1.4.12 but I would understand if you didn't want to merge a fix on this old branch.

[greg-1-anderson]

This looks good, but it will need to go in on the default branch first. The code should be about the same there.

[prudloff-insite]

There is a PR for the 3.x branch here: #989