Creates a layouts/ folder for keymaps shared between keyboards (#1609)

* include variables and .h files as pp directives

* start layout compilation

* split ergodoxes up

* don't compile all layouts for everything

* might seg fault

* reset layouts variable

* actually reset layouts

* include rules.mk instead

* remove includes from rules.mk

* update variable setting

* load visualizer from path

* adds some more examples

* adds more layouts

* more boards added

* more boards added

* adds documentation for layouts

* use lowercase names for LAYOUT_

* add layout.json files for each layout

* add community folder, default keymaps for layouts

* touch-up default layouts

* touch-up layouts, some keyboard rules.mk

* update documentation for layouts

* fix up serial/i2c switches

layouts/community/ergodox/dvorak_intl_squisher/readme.md

@@ -0,0 +1,29 @@
+# ErgoDox EZ Dvorak International Squisher
+
+Dvorak layout adjusted with several (linux) applications in mind:
+
+* Easier Escape for VIM
+* Windows/Super key for awesome WM
+* Alt+Shift for international characters
+* PrintScreen for sys-rq
+* Insert for the X11 clip-board
+
+Major layer changes:
+
+* Common multimedia keys are integrated into layer 0, less common into layer 1
+* No mouse keys
+* Layer 2 is qwerty (for easier gaming & less fortunate keyboard users)
+
+Known issues:
+
+* Alt+Shift does not work reliably (depends on the X11 kb layout? Not
+  entirely clear...)
+
+![layer0](https://i.imgur.com/AL70X44.png)
+![layer1](https://i.imgur.com/k1DcUdt.png)
+![layer2](https://i.imgur.com/nK80mKf.png)
+
+## Changelog
+
+* 2016-03-29
+  * Initial release