Fixed gulp 'pot' task. Fixed typos in translation strings.

gulpfile.js

@@ -98,7 +98,8 @@ gulp.task('default', ['js-libs', 'css-libs', 'fonts-libs', 'ckeditor', 'pdfjs',
 // Extracts translatable strings using angular-gettext and saves them in file
 // openslides/locale/angular-gettext/template-en.pot.
 gulp.task('pot', function () {
-    return gulp.src(['openslides/*/static/templates/*/*.html',
+    return gulp.src(['openslides/core/static/templates/*.html',
+                     'openslides/*/static/templates/*/*.html',
                      'openslides/*/static/js/*/*.js'])
         .pipe(gettext.extract('template-en.pot', {}))
         .pipe(gulp.dest('openslides/locale/angular-gettext/'));

openslides/core/static/templates/legalnotice.html

@@ -1,6 +1,6 @@
 <div class="header">
   <div class="title">
-    <h1 translate>Legal Notice</h1>
+    <h1 translate>Legal notice</h1>
   </div>
 </div>
 

openslides/mediafiles/static/templates/mediafiles/mediafile-list.html

@@ -67,7 +67,7 @@
       <!-- TODO: show filename / title of mediafile -->
       <nav ng-class="getNavStyle(scroll)" class="form-inline">
         <div class="btn-group">
-          <button class="btn btn-default" ng-click="mediafileGoPrevious()" title="{{ 'Previouse page' | translate }}">
+          <button class="btn btn-default" ng-click="mediafileGoPrevious()" title="{{ 'Previous page' | translate }}">
             <i class="fa fa-backward"></i>
           </button>
           <button class="btn btn-default" ng-click="mediafileGoNext()" title="{{ 'Next page' | translate }}">