fix crash when tap on an empty UITextView

Well, in this case, I think we should have to check UITextView is not empty at first.
Otherwise, this will causes an exception:
`'NSRangeException', reason: 'NSRLEArray objectAtIndex:effectiveRange:: Out of bounds'`
Merge pull request #119 from vinhnx/master

Fix crash when tap on empty UITextView
Rendering single page markdown correctly

A problem occurred in the rendered output whenever the body of
content was smaller than a single page (basically, the content
fit inside of the visible bounds of the markdown view).

This fixes that problem.
Merge pull request #121 from Uncodin/i9-bottom-display

Rendering single page markdown correctly
Merge branch 'mods' of git://github.com/audun/bypass into audun-mods
Guard against the assumption of	having a Display Settings object set on	the view

This change prevents a crash in	the attributed string converter	as it tries
to match a display setting to an element.
Merge pull request #128 from Uncodin/audun-mods

Bringing in changes gathered by @myell0w
Merge pull request #129 from myell0w/mods

Fix potential crash when text is nil
Workaround for potential crash of links without URL and title, e.g. [](/sometext)
Merge branch 'master' of https://github.com/Uncodin/bypass into mods