Job Jar/Tubegen replacement

Tubegen is a rather broken "Jack of all trades and master of none." We'd like to split it apart into several programs that each do something simple. The streamline stats program and culling program accomplish two important steps, but there are a couple left:

1. Seed Generation

Generate a set of random seed points at a given density. Input: seed density in seeds / mm^3, image file (in NIfTI or MRIimage, from which to read dimensions) or image dimensions in mm. Output: list of seed coordinates (one seed per line) written to a file (or standard output if no file is specified).

2. Streamline Generation

Read in a list of seed points and generate streamlines from them, terminating the advection process according to a threshold criterion and a curvature criterion. Input: list of seed coordinates (from a file, or standard input if no file is specified), a diffusion tensor image (as NIfTI or MRIimage), an optional curvature criterion (with a default value), an optional scalar image (as NIfTI or MRIimage), and an optional scalar threshold. Output: a curve collection, either as a trackvis .trk file, a .ccf file (your format), or in CCF format to standard output if no filename is specified.