Merge branch 'master' into csstheming

# Conflicts:
#	src/elements/PageTitle/PageTitle.module.css
#	src/elements/Preview/Preview.module.css
#	src/elements/SideBar/SideBar.module.css
#	src/index.css
#	src/pages/Player/Player.js
#	src/pages/Player/Player.module.css
#	src/pages/SettingsPage/SettingsPage.module.css

src/elements/Preview/Preview.js

@@ -39,7 +39,7 @@ class Preview extends React.Component {
             <div className={style.videopreview + ' ' + themeStyle.secbackground + ' '+ themeStyle.preview} onClick={() => this.itemClick()}>
                 <div className={style.previewtitle + ' '+ themeStyle.lighttextcolor}>{this.state.name}</div>
                 <div className={style.previewpic}>
-                    {this.state.previewpicture != null ?
+                    {this.state.previewpicture !== null ?
                         <img className={style.previewimage}
                              src={this.state.previewpicture}
                              alt='Pic loading.'/> :