Merge pull request #19 from anvk/remedialContent

Adding Remedial Content feature into ATutor
Issue-5149: Fixes content directory path while installing on windows.
Merge pull request #20 from geetakshi/ISSUE-5149

Issue-5149: Fixes content directory path while installing on windows.
ISSUE-5134: Fixes the hard coded table prefixes.
Merge pull request #21 from geetakshi/ISSUE-5134

ISSUE-5134: Fixes the hard coded table prefixes.
add WIRIS math editor to tinymce plugins
math editor adjustments
adjust path to store gernated math images in the content dir
Adding proper randomization algo for the tests
Some of the code refactoring.
More code optimizations
Replacing all tabs with spaces
5107 added a check to see if there are any requests before the foreach
Merge branch 'master' of github.com:atutor/ATutor
fixed typo in path for request instructor account
Password error vulnerability fix
added system pref to allow admins to disable create course tab for instructors
Tiny code refactoring
replaced disable_create for admin's with check for services
remove pass by referecne & when generating the module list for a course when deleting.