grunwaldlab/poppr: poppr version 2.3.0

This version of poppr introduces the function bootgen2genind() that allows you to use aboot() with distance functions that explicitly expect "genind" objects:

There are other various bug fixes and improvements, which are listed below.

• The function bootgen2genind() will help users take advantage of bootstrapping distance functions from other packages that require genind objects. For details, see https://github.com/grunwaldlab/poppr/issues/112 and https://github.com/grunwaldlab/poppr/issues/111

• There is now a plot parameter for the genotype curve to enable or suppress plotting.
• Progress bars are now automatically suppressed when running non-interactively. to turn them on when running non-interactively, use options(poppr.debug = TRUE).
• The progress bar for ia() and poppr() will now show estimated time. This is from dplyr's progress_estimated().

• The hist argument in the ia() is deprecated in favor of plot.
• The x axis for the genotype_curve() plot is now numeric, allowing you to fit a smoothing function over the points without having to use the hack geom_smooth(aes(group = 1)). This is thanks to Kara Woo for pointing this out on twitter (https://twitter.com/kara_woo/status/783336540407685120).
• The "show" method for genclone objects now delimits populations and strata by a comma, avoiding confusion with multi-word population names. Thanks to @knausb for the fix in https://github.com/grunwaldlab/poppr/pull/116.
• Documentation for poppr.amova now contains a note about significance testing with the ade4 function randtest.amova.

• The subsetting methods will now properly handle mlgs when using sample names to subset genclone and snpclone objects. See https://github.com/grunwaldlab/poppr/issues/114 for details.
• A plotting bug for mlg.table() was fixed so that the plots now show the maximum value.
• Bugs with subsetting bootgen and bruvomat objects with no loci specified were fixed. See https://github.com/grunwaldlab/poppr/issues/118 for details.