Add ASCellNode type assertions (closes #161).
Merge pull request #164 from facebook/input-validation

Add ASCellNode type assertions (closes #161).
Remove CATransaction hack.

ASRangeController previously enqueued display of individual nodes by
adding their views to the hierarchy, wrapping each `-addSubview:` call
in an explicit CATransaction to force displays to occur in order.  This
hack is no longer necessary -- kill it.
Merge pull request #165 from facebook/transactions

Remove CATransaction hack.
Fix crash while deleting multiple sections
Another case for deletion
Skip creating placeholder if there is no size

fixes #158
Merge pull request #171 from facebook/issue-158

Skip creating placeholder if there is no size
Merge pull request #168 from facebook/editing

Fix crash while deleting in multiple sections
Fade out placeholders

Added an API to fade out a node's placeholder when it is finished rendering.

fixes #156
fix inserting sections bug
Merge pull request #172 from facebook/fade-in

Fade in placeholders
fix
Merge pull request #177 from facebook/fix_insert_section

Fix insert section
Only create a placeholder with a valid size

fixes #179
Merge pull request #180 from facebook/issue-179

Only create a placeholder with a valid size
Disable ASMultiplexImageNode debug logging.
Merge pull request #181 from facebook/logspam

Disable ASMultiplexImageNode debug logging.
make reloadData thread safe
use asyncDisplayNodePerformOnMainThread