Amethyst 0.17.0

Support for extending existing layouts with custom layouts.
- Note: this includes a fix for encoding of window frames provided to getFrameAssignments that is a potentially breaking change for some custom layouts.
Support for setting a maximum number of displayed windows. Thanks, @MutatingFunc !
Support for disabling screen padding on native display. Thanks, @anthdono !
Support for XDG config hierarchies. Thanks, @cowboy-bebug !
Fix for not respecting option to not follow windows through space transitions. Thanks, @EvanDorsky !
Fix for incorrectly considering small windows.
Fix for an incorrect handling of lack of floating definition.

adds rest of layouts to sample config file by @dmartzol in #1307
Fix small typo by @max-sixty in #1312
Add autominimize setting (AKA window limit) by @MutatingFunc in #1083
Support XDG config by @cowboy-bebug in #1324
Send console.log in custom layouts to syslog by @rickythefox in #1322
Window limit by @MutatingFunc in #1319
Issue 1306: Fix "Follow thrown windows between spaces" setting not working by @EvanDorsky in #1333
Added option to disable screen padding on built-in display by @anthdono in #1293
Always treat quick swapped windows as "tabs" by @ianyh in #1360
Fix consideration of small windows by @ianyh in #1362
Fix the negative logic of floating list by @ianyh in #1363
Allow extending existing layouts by @ianyh in #1366
A slew of dependency updates by @ianyh in #1368
Update min os version in readme by @ianyh in #1369