version 0.3.00

Changes:
- all tools are integrated into the bart command (e.g. call "bart pics ...")
- new tools: mip, lrmatrix, estdims, filter, estvar
- mip: maximum-intensity projection
- estdims: estimate dimension ffrom non-Cartesian trajectories
- lrmatrix: (multi-scale) low-rank decomposition and matrix completion
- filter: median filter
- estvar: estimate noise variance from calibration matrix
- removed deprecated tools: sense, relnorm
- pics: multi-scale low rank regularization
- pics: new options (scale factor, warm-start)
- threshold: added divergence-free wavelet, locally low-rank, and wavelet thresholding
- phantom: 3d image-domain + k-space
- homodyne: various improvements and new options
- new command-line completion script for bash shell
- remove dependency on GSL
- library: improved processing of command-line options
- library: least-absolute deviation using reweighting (lad.c/h)
- library: relax cuda fft constraints
- library: multind/vecops functions for comparisons
- library: add {less,greater} than or equal to prox functions
- many other bug fixes and enhancements