OptiWrangler source code

Following is a brief description of the source code files:
* OptiWrangler.scala: Top-level file
* WranglerTable.scala: Definition of the table data structure and all the transforms. This file has the bulk of the code
* Range.scala: Defines the Range data structure (eg: Range (0,100)). However, although this was used extensively in the initial stages, almost all references to it have now been substituted with calls to array_fromfunction. I'll soon be removing the Range data structure completely from the source code.
* Condition.scala: Defines the Condition data structure passes in as input to the Filter transform. There is a bunch of parameters based on which a row could be filtered out. Abstracting this parameter-collection as a single object  keeps the interface clean. However, currently, the only operation supported is filtering of empty rows. More filtering options (eg: those based on regex patterns) will be added. Before that, I need to figure out how the use of regexes can be staged.