fixed dropdown menu styles; adjusted default app styling

...oad-button-inverse/download-button-inverse.component.html

...oad-button-inverse/download-button-inverse.component.scss

...nload-button-inverse/download-button-inverse.component.ts

...etwork/network-menu-left/network-menu-left.component.html

...etwork/network-menu-left/network-menu-left.component.scss

...twork-menu/download-button/download-button.component.html

...twork-menu/download-button/download-button.component.scss

...network-menu/download-button/download-button.component.ts

...mponents/network/network-menu/network-menu.component.html

...mponents/network/network-menu/network-menu.component.scss

src/index.html

src/index_static.html

src/stylesheets/default-theme.css

src/stylesheets/theme-styles.scss

src/stylesheets/theme.css