LMS: revises CSS reference/pipeline architecture to handle IE9 selector limits

.gitignore

lms/envs/common.py

lms/static/sass/application-extend1.scss.mako

lms/static/sass/application-extend2.scss.mako

lms/static/sass/application.scss.mako

lms/static/sass/elements/_typography.scss

lms/static/sass/ie.scss

lms/static/sass/vendor/_font-awesome.scss

lms/static/sass/views/_verification.scss

lms/templates/courseware/courseware-error.html

lms/templates/courseware/courseware.html

lms/templates/courseware/gradebook.html

lms/templates/courseware/info.html

lms/templates/courseware/instructor_dashboard.html

lms/templates/courseware/news.html

lms/templates/courseware/progress.html

lms/templates/courseware/static_tab.html

lms/templates/courseware/syllabus.html

lms/templates/discussion/index.html

lms/templates/discussion/single_thread.html