- code format for #1020

HTML tags are no longer processed for special links, etc
Contents of <a>, <code> and <pre> are not processed for special links
Processing for special links is done after Markdown conversion

The "PHP" formatting function doesn't add anything, except an undocumented date format.

All usages in the templates have been replaced with DateFmtShort and DateFmtLong for convenience.

Fixes #921 and makes the Mention regexp be in line with the others

- modules/base/markdown.go: fix issue link issue
- routers/repo/view.go: remove useless code

- conf/locale: add mew translator profile

- update russian locale

Fix link to user profile, update based on adjusted MentionPattern

Correction for #723
Bug was : decode failed if the password contains ```:```

Related to #700

In the original bug report it was referencing only the sytem avatar images for setup users (like in the header); however the problem also persists with things like commit history.

This commit fixes the `tool.AvatarLink` function so that it also uses the already existing `avatar.HashEmail` function.

I also refactored the `tool.AvatarLink` method some to make the control flow more apparent and adhere better to DRY (there were multiple calls to the `EncodeMd5` function that the `HashEmail` function call replaced, now there is only one.)