Viewer Error Messages improvements

Added error icon image

Modified gitignore

Added bootstrap styles and updated widget classes

Re-styled notification widget

Using generic GWT version (latest)

Adding new space char to linker

Split widget and panel into 2 classes

Enum with text strings for different notifications

Updated display registration widgets

Updated references to notification and registration widgets

A retry counter for certain messages

Object cleanup

Not showing notifications if Viewer has data

Incrementing app engine version

Moved Use Google Chrome notification

Fixed hide issue

Added variable delay timers