NEW FEATURES:
- introduced SHKFormFieldCellTextLarge, which will replace SHKFormControllerLargeTextField.
- applied to SHKLinkedIn.
- SHKFormController field validation mechanism. Send button is enabled, only if all fields pass validation.
NEW FEATURE: placeholder feature added to SHKFormFieldCellLargeText
NEW FEATURE: LinkedIn posts can now be public or connections-only. Fix for #341
NEW FEATURE: clip with image for large text cell
NEW FEATURE: SHKFormFieldCellTextLarge shows image thumbnail
NEW FEATURES: SHKPlurk made perfect

- got rid of SHKFormControllerLargeTextField
- user can choose qualifier
- user can set private post
SUBMODULE UPDATE: facebook-ios-sdk. Fixes #771 - Facebook errors
NEW FEATURE: file share now has its own icon with file extension in SHKFormFieldCellLargeText
REFACTORING: Facebook now uses SHKFormFieldLargeText instead of SHKFormControllerLargeTextField
NEW FEATURE: SHKFacebook can autoshare. This can be globally switched off in configurator - Facebook sharer inherits default ShareKit behaviour, finally.
REFACTORING: removed config item SHKActionSheetSubclass, as this is exposed to host app and everybody can use his own subclass directly. Exposed creation methods for easier subclassing of SHKActionSheet. Discussed in #771
REFACTORING: minor documentation change
Update README.md

updated with new features (ARC, blocks, new UI)