[fix #1248] [installer] provide switch to leave .emacs untouched

[sankalp-khare]

Provide an option in the installer to not perform the backup/move action on the user's .emacs

• Add a command-line switch -m/--no-move-dotemacs in the utils/installer.sh shell script, in the same style as existing switches.
• Add a condition to the if block that performs the .emacs move-to-backup-location action.
• Update changelog.

note: none of the existing installer options are documented in the doc/installation.md so I didn't change anything there.

---

Before submitting the PR make sure the following things have been done (and denote this
by checking the relevant checkboxes):

• The commits are consistent with our contribution guidelines
• You've updated the changelog (if adding/changing user-visible functionality)
• You've updated the user manual (if adding/changing user-visible functionality like modules, commands, configuration options, etc)

Thanks!

[sankalp-khare]

This was just done for consistency with the rest of the one-line-description args documented in the comment block.

[bbatsov]

note: none of the existing installer options are documented in the doc/installation.md so I didn't change anything there.

Great point. Probably we should do this at some point. :-)

What's the problem you're trying to solve with this change? Seems a bit weird not to move .emacs as it will take precedence over whatever is in .emacs.d.

[sankalp-khare]

@bbatsov I filed this due to #1248

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contribution and understanding!

[stale]

This issues been automatically closed due to lack of activity. Feel free to re-open it if you ever come back to it.