templates: enforce more consistency by being less flexible in templates

All pages must define page_nav.

context_bar may only be used on relevant repository pages, and the 'current'
parameter is mandatory.

rhodecode/templates/base/base.html

@@ -51,20 +51,14 b''
 <!-- END FOOTER -->
 
 ### MAKO DEFS ###
-<%def name="page_nav()">
-    ${self.menu()}
-</%def>
-
 <%def name="breadcrumbs()">
     <div class="breadcrumbs">
     ${self.breadcrumbs_links()}
     </div>
 </%def>
 
-<%def name="context_bar(current=None)">
-  %if c.repo_name:
+<%def name="context_bar(current)">
     ${repo_context_bar(current)}
-  %endif
 </%def>
 
 <%def name="admin_menu()">

rhodecode/templates/forks/forks.html

@@ -9,6 +9,10 b''
     ${_('Forks')}
 </%def>
 
+<%def name="page_nav()">
+    ${self.menu('repositories')}
+</%def>
+
 <%def name="main()">
 ${self.context_bar('showforks')}
 <div class="box">

rhodecode/templates/pullrequests/pullrequest.html

@@ -8,6 +8,10 b''
     ${_('New pull request')}
 </%def>
 
+<%def name="page_nav()">
+    ${self.menu('repositories')}
+</%def>
+
 <%def name="main()">
 ${self.context_bar('showpullrequest')}
 <div class="box">

rhodecode/templates/pullrequests/pullrequest_show.html

@@ -8,6 +8,10 b''
     ${_('Pull request #%s') % c.pull_request.pull_request_id}
 </%def>
 
+<%def name="page_nav()">
+    ${self.menu('repositories')}
+</%def>
+
 <%def name="main()">
 ${self.context_bar('showpullrequest')}
 <div class="box">

rhodecode/templates/pullrequests/pullrequest_show_all.html

@@ -8,6 +8,10 b''
     ${_('Pull requests')}
 </%def>
 
+<%def name="page_nav()">
+    ${self.menu('repositories')}
+</%def>
+
 <%def name="main()">
 ${self.context_bar('showpullrequest')}
 <div class="box">

rhodecode/templates/search/search.html

@@ -29,7 +29,9 b''
     %endif
 </%def>
 <%def name="main()">
+%if c.repo_name:
 ${self.context_bar('options')}
+%endif
 <div class="box">
     <!-- box / title -->
     <div class="title">