Fix various issues

[shgysk8zer0]

List of significant changes made

• Add ability to open feeds in adjacent tab New tab should open popup right next to current tab #94
• Catch & ignore some errors Awesome RSS clutters up the Browser Console with uncaught errors #90
• Update layout of subscription options "Subscribe Using" layout is confusing #96
• Vertically center inputs & icons
• Make ESlint warn on console.* usage Awesome RSS clutters up the Browser Console with uncaught errors #90
• Fix overflow & wrapping of long feed titles Popup breaks with long feed titles #93
• Fix light theme icon color Light theme color is off from other (native) icons in URL bar #91