Notable changes:

• Remove browser from package #775 (@pbklink)
• Fix add component tab positioning #776 (@pbklink)
• Important Note: This PR removes the height property from .lm_drop_tab_placeholder in goldenlayout-base.less (and .scss). If your application uses a copy or derivative of this file, you will need to make the same change in your copy/derivative.
• Improve handling of rounding when calculating areas #777 (@pbklink)
• Fix #774 via #778, rework unload handling (@pbklink)
• Fix #779 via #781 and #786, improve component sizing (@pbklink)
• Update dependencies #784 (@pbklink)
• Add support for proper ComponentItemConfig in DragSource #785 (@pbklink)