ldoc has a magical `@classmod` module type which tries to detect
what is a method and what is a static function. It fails about as
often as it works. This commit makes everything explicit to remove
such issues.
Fixes#2640
Ref #1373
* Move table functions out of awful.util into new gears.table
* travis: Use v9999 prefix for full requests
Make sure no newly deprecated functions are used
* Move all `awful.util.table.*` calls to `gears.table.*` calls
Move table test functions from awful/util_spec to new gears/table_spec
Change awful.util.subsets call to gears.math.subsets in awful/key.lua
Emmanuel Lepage Vallee
Yauhen Kirylau
Kevin Zander
Uli Schlachter