Remove tablesorter

We haven't used it for a while now.

src/root/build.tt

@@ -15,7 +15,7 @@
 [% END %]
 
 [% BLOCK renderBuildSteps %]
-  <table class="tablesorter table table-striped table-condensed clickable-rows">
+  <table class="table table-striped table-condensed clickable-rows">
     <thead>
       <tr><th>Nr</th><th>What</th><th>Duration</th><th>Machine</th><th>Status</th></tr>
     </thead>
@@ -338,7 +338,7 @@
 
       <p>The following builds have used this build as an input:</p>
 
-      <table class="tablesorter table table-condensed table-striped">
+      <table class="table table-condensed table-striped">
         <thead>
           <tr><th>Build</th><th>Input name</th><th>System</th><th>Timestamp</th></tr>
         </thead>