Merge pull request #118 from JimiSmith/master

Check for null parent in recurseElement
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
Create skewed font if italic font is not found. Assert that fonts exist instead of crashing later.
BOOST_HOME => /usr/local/include
Fix warning
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'`
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.
Move fonts and other constants out to BPDisplaySettings
Properties instead of methods in BPDisplaySettings
Use BPDisplaySettings in BPMarkdownView
Fixed CF memory leaks
Fix minor Analyze warning
Release fonts if necessary
Recalculate less when markdown is updated or view is rotated
Use ContentInsets and don't let contentSize.width be larger than the page width
Rename paragraph spacing attributes
Add initial line spacing display settings