Do not save caret when autolinking

Fixes the following bug: (occurred on Chrome ver. 38)

Write some text, type a link which gets auto-linked then type more
words. The following words will be separated by &nbsp; instead of spaces
which causes undefined line breaking behaviour (no spaces means the
browser has no idea where to break the sentence and breakes them i
random places).
Merge pull request #95 from szymzet/wysihtml5

---

Fixes the following bug: (occurred on Chrome ver. 38)

Write some text, type a link which gets auto-linked then type more
words. The following words will be separated by &nbsp; instead of spaces
which causes undefined line breaking behaviour (no spaces means the
browser has no idea where to break the sentence and breakes them i
random places).

Issue #94 fix