Fix some comments
Set queryMain commands as applied functions
Replace conditional operator with if/else
Give gRex instance the responsibility to format fetched results.

- Pass gRex instance as parameter of Graph constructor.
- Give Graph instance a name property.
Give gRex instance the responsibility to send http requests
Direct use of commandBuilder for building commands

- Rename Gremlin to Pipeline class
- Instantiate CommandBuilder from Graph and Pipeline classes
Rename CommandBuilder to Gremlin. Extract Pipeline class to separate file.
Remove Gremlin instance from Graph instance
Give Gremlin class the responsibility to handle script.
Rename command to pipeline
Rename exec() to add()
Extract variable
Remove unnecessary .then()
Unimplemented methods now throw
Add and fix comments
Fix export of createTypeDefinition. Fix stuffs in function.
Remove transaction cud() function
Update tests to 2 spaces tabs
Use request querystring={} and json=true options
Add rexster version and queryTime data back in the result object