basic functionality added/still need to add css properties

button added for the map hexbin icons

buttons with background and icons added

fixes issue #623

minor change

indentation fix
hexbin buttons on the right; below layer selector
enlarged button icons
Merge branch 'master' into layer_button
basic functionality added/still need to add css properties

button added for the map hexbin icons

buttons with background and icons added

fixes issue #623

minor change

indentation fix

hexbin buttons on the right; below layer selector

enlarged button icons

opacity change for the layer buttons

button swap
toggle option added to buttons
Update map.css
darker button in active state
Merge branch 'master' into layer_button
Merge branch 'layer_button' of github.com:modilabs/formhub into layer_button
Conflicts on css and js for layer buttons
Merge pull request #1021 from modilabs/layer_button

layer buttons - closes #623