[#71] stubbed in initial add / open dialog from mocks provided
[#95] moved the grey out overlay so it doesn't cover the sidebar, added active state to plus icon/sidebar area, added code to hide the add/open overlay when grey out overlay is clicked.
[#95] wired up grey out overlay to hide the remove project overlay, settings overlay & add new project overlay when clicked
[#95] added active & inactive  states to minus & settings sidebar areas