Prevent anchors from being hidden by header upon a new page load.

Browsers change the scroll position after the page is loaded, and the current 1 ms
delay wasn't long enough for the browser to jump to the anchor. Even then, it appears
another 100ms delay is necessary to adjust the scroll properly:

http://stackoverflow.com/questions/19057731/scrolltop-on-page-reload-doesnt-work-possible-script-conflict

Add a little more of an offset to see a few lines before the anchor.

Closes #1614
Closes #1024

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 8.0.0 (unreleased)
+  - Prevent anchors from being hidden by header (Stan Hu)
   - Upgrade gitlab_git to 7.2.15 to fix `git blame` errors with ISO-encoded files (Stan Hu)
   - Prevent too many redirects upon login when home page URL is set to external_url (Stan Hu)
   - Improve dropdown positioning on the project home page (Hannes Rosenögger)

app/assets/javascripts/application.js.coffee

@@ -94,16 +94,18 @@ window.unbindEvents = ->
   $(document).off('scroll')
 
 window.shiftWindow = ->
-  scrollBy 0, -50
+  scrollBy 0, -100
 
 document.addEventListener("page:fetch", unbindEvents)
 
-# Scroll the window to avoid the topnav bar
-# https://github.com/twitter/bootstrap/issues/1768
-if location.hash
-  setTimeout shiftWindow, 1
 window.addEventListener "hashchange", shiftWindow
 
+window.onload = ->
+  # Scroll the window to avoid the topnav bar
+  # https://github.com/twitter/bootstrap/issues/1768
+  if location.hash
+    setTimeout shiftWindow, 100
+
 $ ->
   $(".nicescroll").niceScroll(cursoropacitymax: '0.4', cursorcolor: '#FFF', cursorborder: "1px solid #FFF")