first take at #272, needs refactoring
clearer comments
Merge branch 'mb-pages' into layer-list-up
move things around
don't overwrite duplicate layers
move source mapping into sourcelayers template
rename
disable source changing if custom layer list
Merge branch 'mb-pages' into layer-list-up
replace invalid characters in layer list name.
adjust typography in layers panel
cleanup
add validation to layer naming
fix console.log
fix old code
Merge branch 'mb-pages' into layer-list-up
Streamlinify change source/source layer list header.
Small style tweaks.
Handle projects with no stylesheets gracefully.
Add client-side tests for userlayers display.