Reduce magical code for squeezed url

Add method to obtain non-squeezed URL from request path.
add js namespace define file
move window.LDR_VARS to LDR.VARS
add LDR namespace prefix to pref.js config params
move proto to lib/utils
add spec: ApplicationController#url_from_path
Merge pull request #63 from mzp/magical_code_for_squeezed_url

Reduce magical code for squeezed url
Merge pull request #64 from mizchi/js-namespaced

initialize js namespace as LDR and refactor prefs