Add test for e-mail address in status.
E-mail address in status gets detected.

Fixes #96.

Note: Mentions need at least one trailing space before the @.
Add tests for mention detection.
Fix  space before @ of mention after linkifying.
Fix linkifying of mentions at begin of line.

Fixes #96.
Merge pull request #98 from mvitz/fix-mentions-of-emailaddresses

Fix mentions of e-mail addresses in status.