[OF miscellaneous] changes to hilbert curve and new functions
* New functions:
- I added a new function to miscellaneous: idxmatrix.m. It
generates a matrix with elements indicating their own position
(subindexes) in the matrix, i.e. M(i,j) = i * 10 + j
I use it quite a lot in preparing educational material, specially when
explaining functions like reshape, transpose, permute, etc.
Let me know if you have comments or suggestions for improvements.
- I added a function to convert a Hilbert curve to linear matrix
indexes: hc2ind.m 
- I added the usual Makefile to help with the maintenance.
* Changes to Hilbert curve:
I have improved the performance of the recursive function generating
pseudo Hilbert curves: hilbert_curve.m .
I encapsulated the recursion to avoid input checking at each level and
removed calls to helper functions. In my machine I got about 3x
See mail "[OF miscellaneous] Hilbert curve: recursion faster than
loop?" for discussion.
I think it is time to make a new release of the package. 1.3.0?