Fixed update item/{id} uri in ScItemsProvider
Fixed saving fileName in UploadMediaRequestOptions parcel.
Libs updated.
Test fixed.
Merge Volley sources into project. Removed Volley jar.
Removed gson dependency and implemented JSON-simple parsers.
Base ItemsBrowserFragment and ScItemsLoader added.
Code refactoring.
Fixed status code.
Fixed status code in parser.
Merge pull request #7 from Sitecore/libs_refactoring

Libs refactoring
Implemented ability to add custom content provider operations before items are saved to db.
Added caching Item.HasChildren
Code refactoring.
Items browser in progress.
Merge pull request #8 from Sitecore/additional-cache-operation

Implemented ability to add custom content provider operations before items are saved to db.
Merge branch 'dev' into items-browser

Conflicts:
	sitecore-api-android/sitecore-api-android.iml
	sitecore-api-android/src/net/sitecore/android/sdk/api/model/ScItem.java
Fixed parsing Item.HasChildren; GetItemsResponseParser renamed.
Added deleting cached items before new response received.
Various callbacks added.