Improve breakpoints

[ArmorDarks]

• Merge all groups (breakpoints, types, etc.)
• Instead let each breakpoint have settings about should responsive helpers and objects be generated for it or no
• Let select which exactly helpers and object should generate responsive classes for that breakpoint (probably, via list)

Something like:

$ekzo-breakpoints: (
  palm: (
    rule: 'screen and (max-width: #{$ekzo-lap - 1px})',
    generate-responsive: (buttons, grid, spacing, tables, widths)
  ),
  lap: (
    rule: 'screen and (min-width: #{$ekzo-lap}) and (max-width: #{$ekzo-desk - 1px})',
    generate-responsive: ('*')
  ),
  retina: (
    rule: 'screen and (-webkit-min-device-pixel-ratio: 2), screen and (min-resolution: 192dpi)',
    generate-responsive: false
  ),
  vetina: (
    rule: 'screen and (-webkit-min-device-pixel-ratio: 2), screen and (min-resolution: 192dpi)'
  )
) !default;

[ArmorDarks]

Implemented in another form.

I thinks that Let select which exactly helpers and object should generate responsive classes for that breakpoint is a bit too granular approach.

Let's see how current implementation will work out.

[ArmorDarks]

Mentioned above commits made possible even such granular selection.

By default global $ekzo-responsive-helpers-breakpoints controls everything, which is handy, but on occasion you can specify list of breakpoints for any automatically generated responsive helpers. Quite handy.