Update dateformatter.js

Corrected date calculation for day of week
Added/modified day of week tests

This matches PHP:
echo date('N', strtotime('2011-09-06T16:05:02.000Z'))."\n";
echo date('N', strtotime('2011-09-04T16:05:02.000Z'))."\n";
Extract file system based functions into template loaders
added test with include
export loaders
Move loader files, rename, add path resolving to memory loader
Don't use class-based loaders, update some documentation
fix getting parent from cache. closes gh-378
Add page for template loader docs, fix typo
Promot groupBy filter from swig-extras. Closes gh-383
add basic filesystem tests
Extract file system based functions into template loaders
added test with include
export loaders
Move loader files, rename, add path resolving to memory loader
Don't use class-based loaders, update some documentation
Add page for template loader docs, fix typo
add basic filesystem tests
Allow set tag to use bracket notation for object properties
Docs