floatHeaders keep <TH>s on top. Update jQuery to latest 1.x version.

This is a first attempt to keep table headers visible when scrolling.  A feature
requested by PenolopeFudd (https://github.com/PenelopeFudd).  See issue #14 on
github:  #14

THIS REVISION MIGHT NOT WORK AS EXPECTED IN SOME BROWSERS!

The author tested in a fairly recent version of Firefox, where everything works
like charm.  Some quirks where encountered in an ancient Opera (version 12 -
current version is 40.somthing).

We might want to add a commandline switch and/or buttons to turn this feature
on and off (see also 'BUGS' below).

CHANGES

  * Scripts in lib/Devel/NYTProf/js/

    - Include a more recent version of jQuery.  1.12.4 is the most up to date
      version in the 1.x series.  Stored as jqery-min.js again.
      Source: https://code.jquery.com/jquery-1.12.4.min.js

    - Include floatHeaders.js (in a minified version).  MIT License. Sources:
      + https://github.com/mkoryak/floatThead/tree/master/dist - Repo
      + http://mkoryak.github.io/floatThead - Homepage, demo, and download.
      "Release 1.4.4 released 5 days ago (October 3rd 2016)":
          https://api.github.com/repos/mkoryak/floatThead/tarball/1.4.4

  * nytprofhtml:

    - Add 'floadHeaders' to the class attribute of large tables.
    - Add a snippet to initialize the 'floadHeaders' (line 420 and 1501).

BUGS

  * When clicking on a link in the "Top 15 Subroutines" table, the method name
    in the target table is hidden by the floatHeaders.  The floatHeaders script
    does not take anchors into account.

  * Opera 12: floatHeaders are shrunk to a more narrow size by the script.

bin/nytprofhtml

@@ -336,7 +336,7 @@ sub subroutine_table {
 
     my $sortby_desc = ($sortby eq 'excl_time') ? "exclusive time" : "inclusive time";
     $sub_links .= qq{
-        <table id="subs_table" border="1" cellpadding="0" class="tablesorter">
+        <table id="subs_table" border="1" cellpadding="0" class="tablesorter floatHeaders">
         <caption>${qualifier}Subroutines</caption>
         <thead>
         <tr>
@@ -409,15 +409,16 @@ sub subroutine_table {
     $sub_links .= q{</table>};
 
     # make table sortable if it contains all the subs
-    push @on_ready_js, q{
+    push @on_ready_js, q<
         $("#subs_table").tablesorter({
             sortList: [[3,1]],
             headers: {
                 3: { sorter: 'fmt_time' },
                 4: { sorter: 'fmt_time' }
             }
         });
-    } if @subs_to_show == @subs;
+        $(".floatHeaders").each( function(){ $(this).floatThead(); } );
+    > if @subs_to_show == @subs;
 
     return $sub_links;
 }
@@ -461,7 +462,7 @@ $reporter->set_param(
 
         return qq{
         $sub_table
-      <table border="1" cellpadding="0">
+      <table border="1" cellpadding="0" class="floatHeaders">
       <thead>
       <tr><th>Line</th>
       <th><span title="Number of statements executed">State<br />ments</span></th>
@@ -1375,7 +1376,7 @@ sub output_file_table {
 
     # generate time-sorted sections for files
     print $fh qq{
-        <table id="filestable" border="1" cellspacing="0" class="tablesorter">
+        <table id="filestable" border="1" cellspacing="0" class="tablesorter floatHeaders">
         <caption>Source Code Files &mdash; ordered by exclusive time then name</caption>
     };
     print $fh qq{
@@ -1497,6 +1498,7 @@ sub output_file_table {
                 2: { sorter: false      }
             }
         });
+        $(".floatHeaders").each( function(){ $(this).floatThead(); } );
     };
 
     return "";
@@ -1629,12 +1631,12 @@ This file was generated by Devel::NYTProf version $Devel::NYTProf::Core::VERSION
     <title>$title</title>
 EOD
 
-    $html .= qq{<link rel="stylesheet" type="text/css" href="style.css" />\n}
+    $html .= qq{    <link rel="stylesheet" type="text/css" href="style.css" />\n}
         unless $opts->{skip_style};
 
     if (my $css = $opts->{add_jit}) {
-        $html .= qq{<link rel="stylesheet" type="text/css" href="js/jit/$css.css" />\n};
-        $html .= qq{<script language="JavaScript" src="js/jit/jit.js"></script>\n};
+        $html .= qq{    <link rel="stylesheet" type="text/css" href="js/jit/$css.css" />\n};
+        $html .= qq{    <script language="JavaScript" src="js/jit/jit.js"></script>\n};
     }
 
     $html .= <<EOD unless $opts->{skip_jquery};
@@ -1667,9 +1669,10 @@ EOD
             console.log('no match for fmt_time of '+orig+' (units:'+non_number+' charCodeAt0:'+non_number.charCodeAt(0)+')');
             return orig;
         },
-        type: 'numeric' // set type, either numeric or text 
-    }); 
-    </script> 
+        type: 'numeric' // set type, either numeric or text
+    });
+    </script>
+    <script type="text/javascript" src="js/jquery.floatThead.min.js"></script>
 EOD
     $html .= $opts->{head_epilogue} if $opts->{head_epilogue};