Squashed commit of the following:

commit fd3ffc60c65f46f1c5554025ece18f2fd58cfda1
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Thu Dec 11 12:51:19 2014 +0200

    tweaks

    (cherry picked from commit 685e5795e02deb75c78803f2f1c2e82ef3c49663)

commit 66aca05f78de8dadb0cc7c9e978da59794726dd9
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Wed Dec 10 20:30:30 2014 +0200

    Edit diversity-vegan

    (cherry picked from commit 79eb46ece1cac5081f50d4bd84b0c4e8899b2b1c)

commit 2bc1a16c03f11d8886f4ed57ad391e7a5d851e32
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Sun Dec 7 19:04:14 2014 +0200

    Edit diversity-vegan vignette

    Be explicit about extended species richness only concerning
    the number of unseen species and not the total number of species.

    (cherry picked from commit b06ec8328d3083804d2a84ad4b74b67cab41d428)

commit ee9153e2ce44b179eb118611c0e6989e8bdd56bf
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Sun Dec 7 18:14:20 2014 +0200

    Use only the new "exact" variance estimator for Chao bias-reduced

    (cherry picked from commit 9e49c56035bd0ac91b4bd23f2900d57ba4361ff9)

commit 39f7e67a1c30ff84a6dd6263df950d2e7cbe075e
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Sun Dec 7 18:06:39 2014 +0200

    Document the exact Chao bia-corrected variance estimator

    (cherry picked from commit d8253316fc983d4d0ba5a2910a0079b8cffd8852)

commit b150c979190a9288d2aca2291aa50308dee40324
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Sun Dec 7 16:50:53 2014 +0200

    More exact derivation of approximate variance of bias-reduced Chao

    The common texts (and EstimateS web page) use approximate estimator
    for bias-corrected Chao estimate. This uses derivation for the basic
    estimator but replaces terms with those of bias corrected form
    (a1^2 -> a1*(a1-1), 2*a2 -> 2*(a2+1)). The used form is unpublished
    as such, but it follows exactly the derivation as given in Chiu et al.,
    web appendix. The numerical differences between forms are tiny: in
    BCI the maximum difference is ca. 0.02%, and in the 'mite' data up to
    12% -- it seems that difference vanishes as the sample size (no. of
    individuals) increases.

    (cherry picked from commit b7f92c6fb41288c3e441e14acc044bb0ce748e26)

commit e2332b369d9b7df79545819406336db3662202b7
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Thu Dec 4 20:28:49 2014 +0200

    Formatting of diversity vignette

    (cherry picked from commit d24db8b233328d961ea77c65e46f9531b5ee418e)

commit 1ed473db86678e0070de068dbe3324952386589d
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Thu Dec 4 17:14:40 2014 +0200

    Edit description of Chao estimates in the diversity vignette

    (cherry picked from commit d689ed87db134f5da95c24485a2f54e4847b7703)

commit 0b6e8af9c070084fba41e99c0578293e3f42de45
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Thu Dec 4 13:11:29 2014 +0200

    Use simpler expression for the variance of Chao extrapolation

    The new expression uses lower power or one multiplication less than
    the old one. The old one directly lifted from the literature, and
    it is mathematically equal to the new one.

    (cherry picked from commit 92db96cb09a3191add7464220777ca9cfcf97e27)

commit 3aef904857191eb6f69d840adb57254ff7c82253
Author: Jari Oksanen <jari.oksanen@oulu.fi>
Date:   Mon Dec 8 12:39:35 2014 +0200

    typo reported by Olivier Missa at ens.fr
    (cherry picked from commit 199131ed12c5c514223f8681121eabf6e516a6b2)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/vegan@2918 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
NEWS about new variance estimator for Chao in estimateR

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/vegan@2919 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
update NEWS.html


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/vegan@2920 edb9625f-4e0d-4859-8d74-9fd3b1da38cb