Fixes #301.

Fixes #299.

Fixes #303.

Fixes #301.

Fixes #298

Fixes #295.

Fixes #283.

We use BitmapFactory.Options#inJustDecodeBounds to
decode the width and height of images before
decoding the full image so that we can downsample
large images to avoid memory pressure. To do so,
we use mark/reset on a buffered InputStream. To
handle images with large headers, we set a large
(currently 5mb) mark limit. However, there's
always the chance that that limit is insufficient
even with a well formatted image and a bug
free decoder. Since downsampling is typically an
optimization, if such a failure occurs we still
want to decode the full image, even if we can't
obtain the dimensions. By enforcing we don't read
beyond our limit, we ensure that the header read
fails recoverably, so that the full image can
still be decoded.

Fixes #286

-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=82270509

-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=82003436

isDetached seems like the wrong thing to assert here since isDetached has to do with whether the fragment has UI or not. It could still be alive and attached to an activity. See http://developer.android.com/reference/android/support/v4/app/Fragment.html#isDetached().
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=81815183

-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=81384031

fixed the getRoundedSampleSize() calculation bug

Add an original size constant.

Fixes #257

Fixes #276

Feature list preloader support multiple target sizes

rename preloadItem(List<T> items, int position, boolean isIncreasing) to preloadAdapterPosition(List<T> items, int position, boolean isIncreasing)

Fixes #270.

Split interface to provide the size seperatly. Change interface on `PreloadModelProvider` so preload items will requested one by one.
 - introduce new interface `PreloadSizeProvider`
 - change `PreloadModelProvider` preload items will requested one by one.
 - adapt Tests
 - adapt Samples
 - add two sample implementation for `PreloadSizeProvider`
      - `FixPreloadSizeProvider` to provide a size with a fixed width and height
      - `ViewPreloadSizeProvider` provide a size request from a given view using a `OnPreDrawListener`

In your examples the ListAdapter and the final ListPreloader are
strongly connected. Using an Interface will remove this strong
connection.

Using an interface that an Adapter can implement has the following
advantages:
1. the dimensions don´t must be passed to the ListPreloader while the Adapter has the first access to the dimensions of the ImageView
2. you don´t have to pass the items to the ListPreloader, while the
Adapter already has the newest set of items (e.g.: CursorAdapter)
3. in most cases the ListAdapter already has an RequestBuilder, so
you don´t have to pass them twice
4. you get rid of an extra class (ListPrelaoder) you have to implement