[SDK] support for high camera preset (default for high-end devices); small updates to documentation
[README] updated documentation
[Pdf417MobiDemo] updated comments
[SDK] better support for custom camera UI; support for reading PDF417 barcodes in uncertain mode; documentation updates
[Pdf417CustomUIDemo] updated custom UI demo application (torch example)
[SDK] updated SDK and javadoc
[SDK] added torch button to default user interface; bugfixes