Accomodate upcoming change in package Matrix (fixes #415)

[jaganmn]

Finally got around to working on this. A few comments:

• Perhaps verify that I haven't introduced whitespace issues. I noticed that my Emacs inserted tabs where the file otherwise had none. Well, I fixed whatever I saw ...
• Unrelated to the issue, I replaced 5 lines of code repeated throughout the file with a macro. It was too upsetting ...
• I noticed that in several places you have ncol + 1, where ncol is an int. Note that ncol may take the value INT_MAX and in that case ncol + 1 will overflow. The patch does not attempt to address this.
• I've used R_alloc somewhere, but maybe that is not idiomatic ... I needed to do a[i]++ and did not feel like checking whether that was legal for a of type IntegerVector rather than int * ...

[eddelbuettel]

Thanks for the follow-up! I had getting back to you on the TODO list has I was left a little bewildered and lost about what you wanted me to do. Will peruse the PR -- thanks for sending it in!

[eddelbuettel]

Old school :) Maybe we have too much C around R to not let go of macros.

[eddelbuettel]

This looks pretty good, and is actually not code I have been looking at much (all this was part of a nice Google Summer of Code project).

Could you add an entry to the ChangeLog in standard Emacs ChangeLog mode (ie two spaces between date and name, and between name and email?

[eddelbuettel]

Thanks!