Implemented configurable number of columns (PR #74) by @marius7383

create $gl-mq-width variable to choose between min-with and max-width for mediaqueries (max-width by default)

Refactor gridlex-var with new array for breakpoints

Version 2.5.0 change the way to hide columns

Now hidden a column can be achieved with helpers which are composed by breakpoint-keys:
ie.

Note that helpers are not collapsed to col by an underscore (_)

/!\ col-0 and _xs-0 et al. are no more used

• Fix selector attributes
• Fix equalHeight
• Fix hidden helpers

/!\ The version 2.4.0 is now only sass !
The last LESS version is the 2.3.7.

You can now use you own breakpoints.

#38 Add the possibility to order col only based on mediaqueries (ie. col_md-first_lg-last)