Minor - Added documentation to function "addDir" in student_publication (work tool)
Merge remote-tracking branch 'origin/1.9.x' into 1.9.x
Adding AND only if there are filters.
Adding custom petition only when there are more than one course

see BT#6449
Fixing get_sessions_admin() query
Merge branch '1.9.x' of ssh://github.com/chamilo/chamilo-lms into chamilo19
Commenting unused query see #7033
Minor - fixing PHP warnings.
Adding custome conditions see BT#6449

$onlyAddFirstCoachOrTeacher to course session
$removeAllTeachersFromCourse
Minor fixing if session field value is not set.
New changes are not affected by the add_teachers_to_sessions_courses.
Minor - adding comments.
Css upgrade Chamilo Celeste default
modification of default CSS Chamilo, fixes some broken rules is amended by learnpath new icons and add new images to css
modification of default CSS Chamilo, fixes some broken rules is amended by learnpath new icons and add new images to css
add icons scrom
merged changes by aragonc
modification of the loading position of the theme css default.css
Finetuned CSS loading order in template.lib.php
add check lession procees