Add download stats.
Merge pull request #385 from square/dimitris/download-stats

Add download stats.
Create Options only when needed

Create `BitmapFactory.Options` only when resizing or giving a custom `Bitmap.Config`
`createBitmapOptions` will translate given `Request` to `BitmapFactory.Options`
Introduce `requiresInSampleSize` to determinate if computation of sample size is required
Added suggested chchchanges
Fix TargetActionTest.
Remove spaces, reformat JavaDoc
Merge pull request #387 from square/dimitris/fix-tst

Fix TargetActionTest.
Merge pull request #386 from eveliotc/no-options-no-cry

Create Options only when needed
If custom transformation fails, do not invoke stats.
Merge pull request #392 from square/dimitris/null-fix

If custom transformation fails, do not invoke stats.
Clarify documentation on config to note it's a prefered value.
Merge pull request #393 from square/jw/doc-clarification

Clarify documentation on config to note it's a prefered value.
Bracket.
Merge branch 'master' into disk-cache
Add disk cache to new NetworkBitmapHunter tests