Fix navbar height problem in fruitsalad theme

The navbar is missing some vertical spacing, which turns out to be because the line-height defined for the global li selector overrode the line-height for #submenu Fix this by also adding the rule under #submenu li.
Fix some invocations of render_inline_program_qsd

The user argument of render_inline_program_qsd was removed in
f796499. Update the new student reg templates accordingly.
Merge pull request #968 from learning-unlimited/studentreg-template-fix

Fix some invocations of render_inline_program_qsd
Fixes bug with virtualenv pre-activation

Travis uses its own virtualenv install, and has the activate script
located differently than us, and activates it before running manage.py.
This causes the check for our activate script to fail.

Fixes this problem by catching IOErrors, and not raising if the
VIRTUAL_ENV environmental variable has been defined, which would
indicate that the virtualenv has already been activated.
Merge pull request #964 from learning-unlimited/virtualenv-activate-fix

Fixes virtualenv activation
Merge pull request #967 from learning-unlimited/markdown

Add migration to remove leading spaces from QSDs
Revert "Fix navbar height problem in fruitsalad theme"

This reverts commit 7d503912cddb40d6d144b64ef1c0212652088995.
Add line-height attribute to fruitsalad main.less
Merge branch 'main' into mit-theme-tweaks
Merge pull request #959 from learning-unlimited/mit-theme-tweaks

Fix navbar height problem in fruitsalad theme
Merge branch 'main' into mit-prod