Fixed a couple of bugs

- Restored some of the responsive functionality of the "open in new window" checkbox that PG editor 1 had and was lost on the move to tabber (the old and the new)
- Changed it so that if you do save as in a new window, then using view in a new window from that window actually opens a new window.
Fixed bug with export achievements
fixed a bug where you couldn't undo a mark all correct on the problem grader page.
Scoring achievements provides a link to view the score file (since its pretty obscure)
Changed achievement scoring so that dropped and audit students aren't scored.
Fixed an issue where past answers behaved strangly when a user didn't have any defined sets.
Added some variable checking to a js file that was complaining about null values.
Fixed authen to work with apache 2.4
(cherry picked from commit 2160543f668c4033667bfdbe39108a01fd9331b1)
Fixed incorrect version number
(cherry picked from commit 027e89e649a9f3308b93f8b015d236a78d9afd13)
added config file for apache2.4
(cherry picked from commit afc51c5a51805428c8bb3b07b72a50afc2549e3f)
Upgraded version comparison code to be a bit more robust.
(cherry picked from commit 4bbb9c25efd2b1102c2a7735c6e7f51cf65f40f7)
Added fixes for a couple of other places where remote_addr was used.
(cherry picked from commit 89e229a2fe9b06b8886b2c4b9cc2b764a752ac0d)
I was using an obsolete method to check the apache version number. This *should* work in both apache2.4 and apache2.3 setups.
(cherry picked from commit 912992a4343f80a733c802f1467cab9048ad782a)
Still getting the hang of apache 2.4.  This line changed to allow courses/html to be deliverable by the webserver.
(cherry picked from commit a2d1c4846fd3e596a676bf8052241a1dab4b6d6a)
Further tracking down 2.4 changes.
(cherry picked from commit 409e2d4935708837e6a70778558004f17641e828)
Merge pull request #327 from goehle/apache24for29

Again with the Apache 2.4
Changed the grading link for essay problems.  It no longer keeps track of whether or not there is an ungraded essay problem, but it also runs a lot faster for big courses.
Merge pull request #331 from goehle/essayslow

Essay Optimization Release 2.9 Pull
Made changes suggested in issue #273
Merge branch 'release/2.9' of https://github.com/openwebwork/webwork2 into pgeditor2bug