Can't search backward when using "/e"

Originally reported by: **e-matteson (Bitbucket: [e-matteson](https://bitbucket.org/e-matteson), GitHub: [e-matteson](https://github.com/e-matteson))**

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When using `/e` in a search string to position the cursor at the end of the match, it's not possible to search backwards.

#### Steps:

1. Set evil-search-module to evil-search.

2. Search backwards for a string that appears in the buffer: `?foo/e`, or `/foo/eN`.

#### Observed behavior:

No match is found.

#### System Info

- Evil version: 20160619.2253
- OS: gnu/linux
- Emacs: 24.5.1
- Spacemacs branch: develop (rev. e232eb5)

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- Bitbucket: https://bitbucket.org/lyro/evil/issue/692

Start with the evil-search module and reproduce the reported commands: ?foo/e and /foo/eN. Trace how the /e end-of-match flag is handled for backward searches; done means backward search finds the match and positions the cursor at its end.

Written by the indexing model from the issue text.