[datatable-help] v1.6.4 has been submitted to CRAN

[Matthew Dowle]

NEW FEATURES

    o   DT[colA>3,which=TRUE] now returns row numbers rather
        than a logical vector, for consistency.

BUG FIXES

    o   Changing a keyed column name now updates the key, too,
        so an invalid key no longer arises, fixing #1495.
        Thanks to Chris Neff for reporting.
        
    o   := already warned when a numeric RHS is coerced to
        match an integer column's type. Now it also warns when
        numeric is coerced to logical, and integer is coerced
        to logical, fixing #1500. Thanks to Chris Neff for
        reporting. 

    o   The result of DT[,newcol:=3.14] now includes the new
        column correctly, as well as changing DT by reference,
        fixing #1496. Thanks to Chris Neff for reporting.
        
    o   :=NULL to remove a column (instantly, regardless of table
        size) now works rather than causing a segfault in some
        circumstances, fixing #1497. Thanks to Timothee Carayol
        for reporting.
        
    o   Previous within() and transform() behaviour restored; e.g.,
        can handle multiple columns again. Thanks to Timothee Carayol
        for reporting.
        
    o   cbind(DT,DF) now works, as does rbind(DT,DF), fixing #1512.
        Thanks to Chris Neff for reporting. This was tricky to fix due
        to nuances of the .Internal dispatch code in cbind and rbind,
        preventing S3 methods from working in all cases.
        R will now warn that cbind and rbind have been masked when
        the data.table package is loaded. These revert to base::cbind
        and base::rbind when the first argument is not data.table.
        
    o   Removing multiple columns now works (again) using
        DT[,c("a","b")]=NULL, or within(DT,rm(a,b)), fixing #1510.
        Thanks to Timothee Carayol for reporting.
        
NOTES

    o   The package uses two features (packageVersion() and \href in 
        Rd) added to R 2.12.0 and is therefore dependent on that 
        release. A 'spurious warning' when checking a package using 
        \href was fixed in R 2.12.2 patched but we believe that warning 
        can safely be ignored in versions >= 2.12.0 and < 2.12.2 
        patched.