[R-pkgs] amap new version (multidimensional analysis)

[Antoine]

Dear R users,

Thanks to a new contributor, Luigi Cerulo, amap provides 2 more metrics, 
and another agglomeration linkage for distance computation, and hierarchical
clustering.

The new centroid linkage method implemented in the cluster3
software tool (http://bonsai.hgc.jp/~mdehoon/software/cluster/software.htm). 
In this method the pseudoitem of a cluster is computed as the average of
the items coordinates, and clusters are aggregated with the same
distance metrics used between items. This approach reveals very
effective in the context of gene functional expressions analysis.

This update makes amap even more convenient for gene expression analysis, 
but not only; amap provides a lot of tools for robust statistics (rank 
based metrics, robust principal component analysis) with very fast
implementations.

Antoine Lucas.