Merge pull request #60 from chamilo/1.9.x

1.9.x
Merge branch '1.9.x' of github.com:FraGoTe/chamilo-lms into 6715
Merge branch '1.9.x' of github.com:chamilo/chamilo-lms into 6715
UX improvements - refs #6715
From html form to FormValidator and some JS improvements - refs #6715
from html form to FormValidator - refs #6715
Correct comments and spaces - refs #6715
Rename some variables - refs #6715
Merge pull request #61 from chamilo/1.9.x

1.9.x
Add plugin and re organize the code
Fixe for showing result in header into gradebook cateboris -refs #7153
Modify Path, names and format code - refs bcourse
Fixing funtion load_session_categories in order to load all categories.

See #7153
Minor - format code.
Minor - format code.
Adding session id see #7153
Fixing openmeetings tool see #7167
Minor - format code.
Fixing delete skill see #7168
Minor - format code.