Adjust JSHint options and standardize quote marks

* Alphabetized non-environmental options within each .jshintrc file
* Removed "sub" option from all .jshintrc files
* Pointed Grunt at the correct test spec directory
* Added "quotmark": "single" to enforce consistent use of single-quotes
* Converted all remaining double-quotes to single-quotes
* Fix variable declarations in pvector test spec

Reference: #105