improved the efficiency of tabulate
finished xIsIn
rewrote xSwap in C++
rewriting cJoin in C++
join was slower, so used R
corrected an error in swap
preparing for v0.53
rebuilt manual
improved definition of xTabulate
tiny syntax changes
decided not to use unsigned integers
updated news
re adding .o files
added commit hook
deleted cJoin, as it was killing the buid
updated exports, news
Merge branch 'develop' into releases