Optimize date parsing

[rxaviers]

Make runtime phase lighter. Move weight from runtime to setup phase.

[rxaviers]

Size diff: (significant date size reduction)

   raw     gz Compared to master @ 5d1379688667684fa5754448130d468b4d253dcd    
     =      = tmp/globalize.min.js                                             
     =      = tmp/globalize/currency.min.js                                    
 -1099   -578 tmp/globalize/date.min.js                                        
     =      = tmp/globalize/message.min.js                                     
   +36     +9 tmp/globalize/number.min.js                                      
     =      = tmp/globalize/plural.min.js                                      
     =      = tmp/globalize/relative-time.min.js                               
     =      = tmp/globalize/unit.min.js                                        
     =      = tmp/globalize-runtime.min.js                                     
     =      = tmp/globalize-runtime/currency.min.js                            
 -2034   -881 tmp/globalize-runtime/date.min.js                                
     =      = tmp/globalize-runtime/message.min.js                             
     =      = tmp/globalize-runtime/number.min.js                              
     =      = tmp/globalize-runtime/plural.min.js                              
     =      = tmp/globalize-runtime/relative-time.min.js                       
     =      = tmp/globalize-runtime/unit.min.js  

[rxaviers]

And smarter use of regular expressions, i.e., create necessary regular expression only and do it once.